China - continued
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by
Prof. Hu Zizhi and Dr Zhang Degang
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China - continued
by Prof. Hu Zizhi and Dr Zhang Degang |
| 6. OPPORTUNITIES FOR IMPROVEMENT OF FODDER
RESOURCES
Most grassland in China is in the arid, semiarid or alpine areas where the climate is harsh, communications are poor and the economy backward. The grassland within agricultural and agro-pastoral areas is also scattered in remote places. In this case, the grassland utilization is extensive, mainly free grazing. Utilization methods are based on the natural geographic conditions and grassland productivity. Natural grassland may be divided into three types according to their use (see Table 26).
Grazing and Haymaking Dual Purpose Grassland. Grassland for dual purpose grazing and haymaking is generally on plains with a sward height of 50 cm, more than 50 percent of cover, less than 25º of slope and high quality. The aftermath is grazed. Grassland suited to haymaking is mainly in northern and south-eastern China with >400 mm. of precipitation; it is scarce in the west temperate, arid and semiarid desert and steppe where it is only available in scattered patches on high mountains. Hay land is also available in lowland meadow areas along the rivers and by lakes; it is dominated by Phragmites communis (it is used for hay during early growth, i.e. before the six leaf stage). In spite of high coverage of grass communities on the Qinghai-Tibet Plateau hay land is still scarce since the grass is very short and is scattered in low altitude valleys. Dominant grasses in the valleys are Leymus chinensis, Phragmites communis, Deyeuxia angustifolia, Deyeuxia langsdorffii, Deyeuxia arundinacea, Stipa grandis, Stipa baicalensis, Stipa capilata, Stipa bungeana, Spodiopogon sibiricus, Bothriochloa ischaemum, Themeda triandra var. japonica, Miscanthus sinensis, Miscanthus sacchariflorus, Achnatherum splendens, Elymus sibiricus, Elymus nutans etc. According to the pattern of use, hay land can be divided into permanent and temporary types. Permanent haymaking land is used on the same patches, at the same time of year. Temporary haymaking land is used for hay or grazing, based on the precipitation and thermal conditions of the year and the grass height. Grass is mown once in late summer or early autumn in northern China and twice in summer and autumn in southern China. Harvested grass is mainly for hay and used as a supplement in winter and spring; a little is sold. Some high quality hay, such as Leymus chinensis is exported to Japan and Korea. It is not usual to make silage in pastoral areas. Grazing. Grazing is the most important and essential method of using natural grassland. The area of grazed pasture is 264,204,900 ha, which accounts for 75.25 percent of national grassland. Grazed pasture has the following aspects: < 30 mm sward height or as for haymaking, but with an uneven surface, > 25º degree of slope, low quality grass and unsuitable for hay. Based on topography, seasons of use and water availability, the seasonal belts of grazing land may be divided into spring-autumn pasture, summer pasture and winter pasture or cold season (spring, autumn and winter) pasture and warm season (summer) pasture. Seasonal bands of grassland in the plains of the northeast and Inner Mongolia are not clear and most grassland could be grazed at any time of year. However, seasonal belts of grassland in north-western arid desert areas are clearly defined since high mountains alternate with valleys. Animals graze desert pasture in basins in winter and on the semi-desert and steppe pasture in outlying hills and low mountains in spring and autumn and on the forest pasture and alpine meadows in summer. Stock and herders move as far as tens of kilometres, even 500 kilometres, from winter to summer pasture. Although the grassland on the Qinghai-Tibet Plateau is in the alpine belt or above, it too is divided into warm pasture and cold season pasture. The former is in lower valleys and the latter in the remote higher mountains. In the past decade, the government put the "Long-term contract grassland use system" into force with great effort. Under this system, grassland productivity is improved by sub-dividing pastures and allocating long-term grazing rights to individual families based on the number of family members, with fencing, establishing a homestead and barn, establishing artificial grassland and building infrastructure for water and electricity supply. This has been basically completed nationwide, but it is not totally applied on summer pastures because of their long distance from settlements, complex topography and difficulty of management. Most herders began to adopt extensive rotational grazing systems and use improved technology from the inception of the system. It also provides a good basis for managing grassland legally. Grasslands which are difficult to use include areas which are:
The area of such land is 19,567,680 ha, or 5.57 percent of the total. Most water-scarce grassland is in Inner Mongolia, Xinjiang and Qinghai, unpopulated areas in north-western Tibet and south-western Qinghai, difficult swamps in Heilongjiang and Sichuan. Grassland Deterioration and Control Strategies Grassland deterioration, a worldwide problem, is severe in China. According to data published in 1994 the national area of deteriorated grassland was 68,000,000 ha. up to the end of 1980s, which is 27.5 percent of the total. It has increased remarkably in the past decade. Now 90 percent of national grassland is reported to show signs of deterioration, in which, moderately degraded grassland is 130,000,000 ha. (32.5 percent of total) and it is accelerating by 20,000,000 ha. per year (Liu Zixue, 2001). The current grassland deterioration in major pastoral regions is shown in Table 27.
Evidence of grassland deterioration is drifting sand, salinization, patch-like distribution and hammada. Its major causes are severe over-stocking caused by long-term uncontrolled grazing, improper land reclamation and abandonment, climate change, collecting firewood and herbal medicine. Grassland deterioration not only results in decline of productivity, but also in environment damage, water and soil erosion, sand and dust storms, and desertification. The government is paying great attention to this situation. As one of its most important targets, ecological environment rebuilding has been covered in the West Development Plan by central government in 2000. In agricultural and agro-pastoral areas, this target will be achieved through returning arable land on slopes of >25º degree to forest and grassland and reducing the number of grazing livestock. Severely degraded pasture will be closed for vegetation recovery in pastoral areas. Simultaneously stock numbers will be reduced with yard feeding so that the vegetation and environment can recover rapidly. The large area of degraded grassland has a severe negative influence on animal production and the environment and causes great concern to the government. According to the "Planning Program of National Ecological Environment Construction" and "Outline of Fifteenth Ten Years Plan", the following should be achieved by 2010: - to increase artificial grassland and improved grassland by 50,000,000 ha; - to improve 33,000,000 ha. of degraded grassland and 20,000,000 ha. of desertified land; - to control of 600,000 ha. of water and soil eroded land; - to return 6,700,000 ha. of arable land (on >25º degree slopes) to forest and grass. These objectives show the resolve of the Chinese people and government to improve degraded grassland and the environment. There are temporary and permanent solutions for grassland improvement. The latter is to establish artificial grassland, which will be discussed below. Closure Closure is to protect grassland from grazing or control grazing pressure strictly through fencing, so that it has a chance to recover. Herbage yield increases rapidly in the humid and subhumid areas but the effect declines over time; closure should not exceed three years. In western China, where the grassland is severely degraded, a large area has been closed to grazing since 2000 and many animals have been culled or are stall fed. Reseeding Reseeding is over-sowing degraded grassland with improved forages to improve sward composition and productivity. Manual methods are used on small areas, but aerial seeding should be used on large ones. The cost/benefit ratio is 1: 2-4, the investment could be recouped within two years. The following details require attention during aerial seeding:
Irrigation Water shortage is a major constraint for grass and animal production since most of China’s grassland is in arid and semiarid areas. Grass yield could be increased by 6 to 9 times through irrigation and the proportion of legumes in the sward could be increased as well, improving nutritive value. In Inner Mongolia, 5 percent of water for agriculture is used for grassland irrigation. Thirty two reservoirs have been built in pastoral areas of Qinghai, their storage capacity is 1,739,000 m3. 512 water channels, totalling 2,190 kilometres, were built to irrigate 40,000 ha. of grassland. The area of irrigated grassland is 140,000 ha. in Xinjiang and 240,000 ha. in Tibet. Surface flooding is the common irrigation method. The problem is that over half of the area can be missed because of poor land-levelling. Sprinkler irrigation is not used in practical situations. Fertilizers Fertilization is important for grassland improvement. A large amount of nutrients is absorbed by grasses, especially highly productive grassland for hay and dual use. The deficit should be supplemented by fertilizing. Dung is widely used combined with chemical fertilizers for artificial grassland establishment. Trace fertilizers and rare earth fertilizers are also applied in some places. On natural grassland the commonest and most practical fertilization application method is night penning, i.e. concentrate animals in one place for two nights and then move them to another. This method can increase grass yield by half in the following year. Surface Tillage Shallow tillage (with surface cultivator) has a positive effect on grass yield on pasture dominated by rhizomatous grasses such as Leymus chinense and Phragmites communis and those with dense sod (dominated by Kobresia spp.). Shallow tillage improves air and water permeability of the soil and enhances vegetative propagation by cutting rhizomes. The yields of grasslands dominated with Leymus chinense, Kobresia spp. and Agropyron cristatum could be increased by 50 to 200 percent. Seed yields of Leymus chinense and Agropyron cristatum can be increased by 180 percent to 1,500 percent. Burning is an old, practical method for grassland improvement. It is no longer used in northern China because the grassland is so severely degraded. It is, however, still widely used in the shrub grassland and swamp grassland in southern China. Forage grasses and artificial grassland Artificial grassland is special agricultural land combining pastoralism with agronomy. Even as the artificial grassland constituted by Lolium perenne-Trifolium is symbolic of the western agro-pastoral civilization, the artificial grassland of Medicago sativa is typical of the eastern agro-pastoral one. China was one of earliest countries to grow Medicago sativa. In 126 BC, China began raising lucerne along the Yellow River, and it was rotated with wheat. Apart from improving crop yield and soil fertility, this system directly and indirectly contributed to forming livestock breeds such as Qingchuan cattle, Jinnan cattle, Zaosheng cattle, Nanyang cattle, Guanzhong donkey, Zaosheng donkey (the donkey is less important than before because of mechanized cultivation and transport). Compared with natural pasture, the area of artificial grassland is small. In 1995 it was 13,800,000 ha, which is 3.4 percent of all grassland. It increased to 15,480,000 ha. in 1997, 3.8 percent and 20,000,000 ha. in 2000, 4.8 percent. Aerial seeding plays an important role for establishment; it began in 1979 and the area of aerial seeded artificial grassland was 2.497,000 ha; by the end of 1998 the established area was 1,472,000 million ha. Among provinces or regions, the artificial grassland areas in Inner Mongolia, Gansu, Xinjiang, Shaanxi and Sichuan are large: over 2,500,000 million ha. in Inner Mongolia and close to 1,000,000 ha. in Gansu. The priority is given to lucerne in all provinces except Sichuan. The lucerne area in Gansu is close to 400,000 ha, which is 34 percent of the national total. Nowadays, cereals, cotton, oilseeds and fruits are in relative surplus in China, but forage is scarce in both urban and rural areas. Besides, environmental deterioration has drawn serious attention to reseeding grassland; returning arable land to grassland and forest is one of 10 projects for reconstruction in western China. It is expected that the development of artificial grassland will be speeded up in the near future. Major Forage Grasses and Forage Crops China has many forage grasses and forage crops. There are more than 100 species of cultivated forage in China; most are legumes and grasses. Among these, over 30 species are sown on more than 10,000 ha. (excluding mixed sowing, see Table 28)
Forage Legumes Around 21 genera and around 60 species of legume are grown in China. The major genera and species are briefly introduced as follows(Cheng Baoshu, 2001; Hong Fuzeng, 1989): Astragalus: Astragalus huangheensis (=Astragalus adsurgens), it is thermophilic, cold resistant, salt tolerant, wind and sand resistant, adapted to sandy land with 300 mm to 400 mm of rainfall and mainly used for aerial seeding for soil protection and forage. Astragalus sinicus, its provenance is in the subtropical area of China from 24o to 35o N and it has been cultivated for more than 600 years, is used as a green manure on paddy fields (inferior 1/3 and roots) and forage (top 1/3) for pigs. It is also a honey resource. Caragana: Caragana korshinskii, Caragana intermedia and Caragana microphylla, sub-shrubs tolerant to cold, drought, wind and sand, can be sown in arid sandy land where the rainfall ranges from 150 mm to 250 mm. Coronilla: Coronilla varia ( a dual-purpose legume for forage and soil conservation). Desmodium: Desmodium. intortum, Desmodium uncinatum etc. Hedysarum: Hedysarum laeve, Hedysarum scoparium, Hedysarum fruticosum (sub-shrubs suitable for temperate areas where the rainfall is 150 mm to 350 mm). Kummerowia: Kummerowia striata, an annual legume with wide adaptation: drought tolerant, flood resistant, photophilic and shade tolerant, and can be sown in tropical, subtropical and temperate areas where the pH values range from 4.1 to 7.5. Lathyrus: Lathyrus sativus, Lathyrus pratense etc. Annual legumes. Lespedeza: Lespedeza bicolor, Lespedeza cuneata, Lespedeza dahurica (all indigenous and widely sown in the north), Lespedeza hedisaroides. Leucaena: Leucaena leucocephala, a shrub or tree with various varieties suited to tropical and subtropical areas. Lotus: Lotus corniculatus. Lupinus: Lupinus luteus, Lupinus albus etc. Macroptilium: Macroptilium atropurpureum, is a tropical perennial creeping legume with high proportion of leaf and high protein content and can be used as both fodder and for water and soil control. Medicago: Medicago sativa (most important and widely sown), Medicago falcata and Medicago denticulata etc. Melilotus: Melilotus alba (widely sown in 1950s and 1960s), Melilotus officinalis, Melilotus dentatus etc. Onobrychis: Onobrychis viciifolia (mainly used in sandy area where the conditions are unsuitable for Medicago sativa through low temperature and rainfall), Onobrychis transcausia, Onobrychis arenaria etc. Pocockia: Pocockia ruthenica (= Trigonella ruthenica, it is a rare legume in the alpine region, extremely cold resistant and with stool shoots). Pueraria: Pueraria lobata (sown in north) and Pueraria thomsonii (sown in south, high starch content in roots), both good both for forage and water and soil conservation. Stylosanthes: Stylosanthes guianensis (introduced). Trifolium: Trifolium repens and Trifolium pratense (mainly sown in the humid hilly area in southern China), Trifolium incarnatum, Trifolium hybridium, Trifolium lupinaster, Trifolium fragiferum, Trifolium subterraneum, Trifolium alexandrinum etc. Vicia: Vicia sativa, Vicia villosa, Vicia faba (used for fodder and green manure, sown in autumn in southern China), Vicia amoena. Cultivated Grasses Around 24 genera and 60 species of grasses are cultivated in China. The major genera and species are briefly introduced as follows: Agropyron: Agropyron cristatum (sown in the northern China), Agropyron mongolicum (adapted to steppe and desert zones) and Agropyron desertorum. Alopecurus: Alopecurus pratense and Alopecurus arundinaceus; are not used much. Arrhenatherum: Arrhenatherum elatius. Bromus: Bromus inermis (has been sown in China for more than 100 years and its cultivated area is increasing in the humid regions of northern China and the Qinghai-Tibet Plateau), Bromus catharticus. Cynodon: Cynodon dactylon (widely used as forage and turf). Dactylis: Dactylis glomerata (sown widely in China and the area is large). Elymus is an important grass and of great value for establishing perennial artificial grassland. Cultivars in this genus are characterized with strong adaptation, strong cold tolerance and easy maintenance. Elymus sibiricus and Elymus nutans were domesticated in the 1950s and are major cultivated grasses in northern China (especially on the Qinghai-Tibet Plateau). They can be sown in pure stand but perform better if the two are mixed. Elymus dahuricus and Elymus excelsus are also cultivated. Elytrigia: Elytrigia repens, Elytrigia intermedia and Elytrigia trichophora. Hemarthria: Hemarthria compressa (mainly grown in the subtropical south-western humid areas and Sichuan). Hordeum: Hordeum brevisublatum and Hordeum bogdanii (used for both grazing and hay with features of hydrophile and salinity tolerance). Leymus: Leymus chinensis (has a wide ecological range and is salinity resistant, with high nutritive value and was sown on a large scale in the 1950s as one of the key cultivars of permanent artificial grassland), Leymus secalinus (is resistant to cold, drought and salinity with strong colonising ability, but its cultivated history is short). Lolium: Lolium perenne (a famous perennial grass, widely cultivated since 1970s; an important forage grass and also the most important turf grass in humid regions) and Lolium multiflorum (mainly sown in winter in rice raising areas of subtropical zone can be grown in the warm Temperate Zone of North China). Paspalum: Paspalum dilatatum and Paspalum wettsteinii (all cultivated species in this genus are introduced and these two are important in tropical and subtropical areas). Pennisetum: Pennisetum purpureum (introduced in the 1930s, is grown in subtropical areas on a large scale). Phalaris: Phalaris arundinacea (is all over China, and is widely sown since it tolerates waterlogging, salt and pests), Phalaris tuberosa (introduced in the 1970s, is cultivated in southern subtropical areas) and Phalaris canariensis (not used much). Phleum: Phleum pratense (is cultivated and widely sown, but the area is small). Poa: Poa pratensis, Poa pratensis var. anceps (wild on the Qinghai-Tibet Plateau and adapts to cold with grazing and cutting tolerance), Poa trivialis, Poa erymophila and Poa compressa. Puccinellia: Puccinellia tenuiflora (domesticated in 1930s) and Puccinellia chinampoensis (both are famous for salinization control). Roegneria: Roegneria semicostata, Roegneria ciliaris (both are widely distributed), Roegneria kokonorica (domesticated in the 1960s and is important for artificial grassland with its strong cold tolerance in alpine regions of Qinghai-Tibet Plateau). Setaria: Setaria anceps (introduced, sown in southern subtropical areas). Sorghum: Sorghum sudanense (introduced in the 1930s and sown nationwide. It is a vital fish fodder). Spartina: Spartina anglica (introduced from United Kingdom in 1963 and widely planted in coastal areas. It is of great value for the improvement of saline coastal areas). Zoysia: Zoysia japonica, Zoysia sinica, Zoysia tenuifolia, Zoysia matrella, Zoysia macrostachya etc. (creeping grasses for grazing, slope consolidation and turf). Other Cultivated Forages Amaranthus paniculatus, annual herb of Amaranthaceae, is a high quality fodder for pigs, poultry and cattle. It is of ancient cultivation in China where the area is the largest in the world. Calligonum mongolicum, the super-xerocole shrub of Chenopodiaceae; a pioneer plant for sand fixation in desert and gravel desert with tolerance to drought and cold. It is usually used for aerial seeding. Ceratoides latens, a shrub of Chenopodiaceae, important in Temperate Zone and alpine desert for artificial pasture with tolerance to drought and cold, and adaptation to sandy and rocky soils. Kochia prostrata, a creeping sub-shrub of Chenopodiaceae, is good forage in desert and semi-desert areas with tolerance to drought, salt, poor soil and a high protein content, and it is suitable for establishing rainfed grassland. Lactuca indica, a biennial herb of Compositeae, indigenous to China and sown country-wide as fodder for pigs and poultry. Silphium perfoliatum, a perennial herb of Compositeae, introduced in the 1980s and is cultivated nationwide as fodder for cattle, pigs and rabbits. Symphytum peregrinum, a perennial herb of Boraginaceae, introduced in the 1970s is widely cultivated between the Great Wall and Yangtze River as pig and cattle fodder. Forage Cereals Avena sativa is the most important fodder crop in the north and alpine areas. It is generally sown pure; the sown area has increased rapidly in recent years because it is easy to grow and harvest. Its seeds do not ripen on the Qinghai-Tibet Plateau, but high quality freeze-dried hay could be got through adjusting sowing time to enable it to complete heading before the frost. Hordeum vulgare is an important forage and its cultivated area is only slightly less than forage maize. It is sown country-wide both in the north (spring barley) and the south (winter barley). Naked barley is the Tibetan staple food. Secale cereale introduced from Russia in 1940s and now widely cultivated in northern and alpine areas. In 1979 an American cultivar "winter grazing 70" was introduced and extended nation-wide. Setaria italica, annual, is indigenous to China and has been cultivated for more than 6,000 years. It is widely sown in the north as a cereal. The nutritive value, palatability and digestibility of its straw are higher than those of wheat and rice. It could be made into high quality hay (not removing the grain) by dense planting. Sorghum bicolor has been cultivated in China for 4,000 years, but its area is much less than Sorghum sudanense and is increasing in recent years. Zea mays is the most important forage in China and sown country-wide in a long, narrow belt from northeast to southwest. It was used as human food before 1980, but now is almost all used as animal feed. Grain Legumes as Forage Cicer arietinum is a dual-purpose crop, introduced from Russia in the 1950s. Now it is cultivated both in the north and the south. Its grain is a very nutritious concentrate. Glycine max is indigenous to north-eastern China and the forage variety is a primitive form. Both green chop and grain are good forage with high protein content. Pisum sativum (white flower) and Pisum arvense (purple flower) are annuals and have been cultivated for 2,000 years in China. It is sown country-wide because of cold tolerance and it is better to mix with oats than Vicia sativa. Vicia faba is a dual-purpose crop and has been cultivated for 2,100 years in China where its cultivated area is the greatest in the world. A forage cultivar introduced in 1960 is cold resistant with high yield and high quality. Root Tuber, Stem Tuber and Melon Forages Beta vulgaris, biennial herb of Chenopodiaceae, is widely grown in the north for sugar (main purpose) and fodder. Fodder cultivars normally cannot grow in alpine regions, but it could be grown and yield well by using plastic sheet mulching. Brassica rapa, a biennial crucifer, is an old cultivated crop. It was mainly grown on the Qinghai-Tibet Plateau in early times and now is extended to the whole country as a succulent fodder. Its yield could be greatly increased by using plastic sheet mulching. Cucurbita moschata, annual Cucurbitaceae, gives high yields and high quality succulent fodder. The contents of carotene, vitamin A, B and C in flesh and fruit are 100 times higher than grain cereals. Daucus carota, biennial of the Umbelliferae, grown country-wide as a succulent fodder. Helianthus tuberosus perennial herb of Compositeae; leaf, stem and tuber can be used. Aquatic Forage Crops Alternanthera philoxeroides, amphibious perennial herb of Amaranthaceae, from Brazil and was introduced in 1920s. Cultivated both in the north and south as fodder for pig, poultry, cattle, sheep and fish. Its dry matter content is less than 5 percent. Aneilema keisak, an annual herb of Commelinaceae, has been cultivated in subtropical southern China for a long time. Its dry matter content is around 5 percent. It grows fast and is used as fodder for pigs, cattle and rabbits. Azolla imbricata, a floating fern of Azollaceae, widely distributed in tropical and subtropical zones; has been cultivated in China for 500 years. It forms a fern-algal symbiosis with blue green algae (Anabena azolla, Cyanophyta) and can fix atmospheric nitrogen. Its yield is as high as 300 to 500 tons/ha. with 16 to 18 percent of crude protein (DM base). It is high quality fodder for pig, poultry and fish, and a good green manure. Eichornia crassipes, a floating herb of Pontederiaceae, is a high yielding aquatic forage indigenous to South America. It is cultivated in the warm Temperate Zone in China. Its dry matter content is around 5 percent. It is used as fodder for pigs, poultry, cattle, sheep and fish or as green manure. Pistia stratiotes, floating herb, of Araceae, is a high yielding aquatic forage in tropical and subtropical zones. It has been extended to the watershed of the Yellow River. The dry matter content ranges from 5 to 6 percent. It is mainly fed to pigs, poultry and fish or is a green manure. Zizania caduciflora, perennial temperate and subtropical grass, long cultivated in southern China. Its height is 1 to 2.5 m and it is high quality fodder for cattle, horses and fish with 14 percent of crude protein. Classification of Artificial Grassland(Hu Zizhi, 1997) Artificial grassland is playing an increasingly important role and its area has increased in recent years. To understand and guide the artificial grassland development scientifically, its classification has been given great attention. Principles of Artificial Grassland Classification The following five principles should be followed for classification:
Classification System and Classification Standards Based on the above-mentioned principles, the classification system of artificial grassland may be constituted with three grades, i.e., class, subclass and type. The classification standards of each grade are described as follows: Class: is divided according to thermal condition. The features of class can be used to guide artificial grassland regionalization. Thermal grade is determined with >0 ºC accumulative temperature (sum theta, see Table 29), totally 5 grades, i.e. tropical zone, subtropical zone, temperate zone, cold temperate zone and frigid (alpine) zone. The thermal values of each zone are shown in Table 29. Class is named with the name of the thermal grade, the 5 Classes are Tropical Zone Artificial Grassland, Subtropical Zone Artificial Grassland, Temperate Zone Artificial Grassland, Cold Temperate Zone Artificial Grassland and Frigid Zone (Alpine) Artificial Grassland.
Subclass: after class Subclasses are divided by soil type. The features of subclass can be used to guide soil improvement and fertilizer regime. Subclass is named by soil type and temperature zone is used as a prefix to express the features of subclass, for example, Tropical Zone Latosol Artificial Grassland, Temperate Zone Chernozem Artificial Grassland, Frigid Zone Alpine Meadow Soil Artificial Grassland etc. Type: after subclass determination, the type is determined according to forage species or species component. The features of type can be used to select cultivation and utilization patterns. Type is named with the forage or forage group. For example, Sorghum sudanense forage, Lolium perenne + Trifolium pratense + T. repens mixture. For convenience of mapping, several types could be merged according to life form, economic group or life span. Connection of Artificial Grassland Classification to the Comprehensive and Consequence Classification System of Natural Grassland The classification system has an inherent relation to the Comprehensive and Consequence Classification System of Natural Grassland; this is embodied in the following points: - First, both systems have three basic grades, Class, Subclass and Type. The thermal, soil and forage species are used as the classification parameters for these three grades in the artificial grassland classification system. This is similar to the Comprehensive and Consequence Classification System of Natural Grassland. Therefore, this system can be called "the Comprehensive and Consequence Classification System of Artificial Grassland". - Second, the temperature could be used as the "interface" to connect the systems because water and temperature are used for class division in both . So, the two systems could be merged and expressed in a unified index chart (see Figure 13). - Third, soil and topography are used for subclass division in natural grassland and soil is used in artificial grassland. Topography is not as important in artificial grassland classification as in natural grasslands. - Fourth, the type of both systems is determined by forage species, so it could be connected directly to compare the aspects of community and grass production. Grass cultivars and seed production The selection and breeding of forage grasses in China can be traced to early times, farmers selected many native forages. However, modern grass breeding began quite late. In the nineteen-fifties two cultivars of Medicago sativa were bred, i.e. Gongnong No. 1 and Gongnong No. 2; breeding has speeded up since 1980. The National Examining and Approval Committee for Forage Cultivars, affiliated to the Ministry of Agriculture, was constituted in 1987. A set of laboratories and experimental stations was set up. There are more than 300 researchers working in forage breeding in 2000. 379 forage cultivars were submitted for registration and 219 were approved by the end of 2000 (44 during 1998 to 2000), including 90 of improved cultivars, 39 of native cultivars, 55 of introduced ones, 35 of cultivated wild varieties. Out of the registered cultivars 17 are Medicago sativa and these can increase yields by 10 to 30 percent.(National Examination and Approval Committee of Forage Grass Cultivars, 1992; Su Jiakai, 2001). In 1986, the National Crop Germplasm Store in the China Agricultural Academy (based in Beijing) was set up It is in charge of long term conservation of crop genetic resources (including forage: seeds can be conserved for over 50 years). In 1989, a Forage Germplasm Store was set up in the Grassland Institute of the Agricultural Ministry. Its storage capacity is 40,000 and it is in charge of midterm conserving and supplying forage germplasm. Meanwhile, five Resource Gardens of perennial forages in Hohhehot, Beijing, Wuhan, Nanning and Kunmimg were set up for field conservation, propagating and supplying germplasm. In 1998, the nationwide Testing Centre of Forage Seeds was founded. All these units, based on the Forage Germplasm Store, combined with the National Crop Germplasm Store and Resource Gardens, make up a national network for conserving, supplying, and testing of forage germplasm. The characteristics of some important cultivars in terms of breeding targets are introduced below (detailed information can be obtained from the National Examining and Approval Committee of Forage Grass Cultivars, contact address: Animal Husbandry and Veterinary Medicine Division, Ministry of Agriculture, Beijing 100026) Early Ripening Cultivars Erect milkvetch (Astragalus huangheensis = A. adsurgens) cannot produce seeds or the seed yield is very low north of the Yellow River because of insufficient accumulated temperature. New cultivars, "Huanghe No. 2", Longmu No. 2" and "Zaoshou" were bred by systematic selection or 60Co-y. Flowering date could be 20 days earlier and the seed yield can be increased by 80 to 120 percent. Lactuca indica originated in the warm temperate and subtropical zones. New cultivars, "Gongnong", "Longmu" and "Mengzao" were bred by mixed selection, and these new cultivars are early maturing, cold resistant and high seed yielders. Cold Resistant Cultivars Legume cultivars suitable for mixed sowing and pure stand are very scarce in northern China. New cultivars of Medicago sativa, "Caoyuan No. 1", "Caoyuan No. 2", "Gannong No. 1", "Longmu 893", "Tumu No. 1", "Xinmu No. 1" and "Xinmu No. 3" were bred using interspecific crossing or intergeneric crossing of M. sativa x M. falcata. Hybrid cold resistant cultivars of Onobrychis viciifolia are "Mengnong" and "Gannong No. 1". Disease Resistant Cultivars Downy mildew is a major diseases of Medicago sativa. "Shingling No. 1" is a cultivar resistant to downy mildew, bred by identifying disease-inoculated strain, selecting, and crossing. Its disease-free rate is 95 to 100 percent. Stylosanthes guianensis is severely infected by anthracnose. "Reyan No. 2" was bred through selection and "907" through 60Co-? for resolving the problem. Salt Tolerant Cultivars A salt-resistant cultivar of Medicago sativa, "Zhongmu No. 1", was crossbred with four good cultivars as parents through open pollination and mix selection for four generations. It enables Medicago sativa to be grown in saline soil and yields can be higher by more than 10 percent compared to ordinary cultivars. Drought and Heat Resistant Cultivars It is hot and dry in the Yangtze River catchment in summer and this is to the detriment of over-summering temperate forages. The new cultivar, "Emu No. 1", was bred from cultivar "Regal" of Trifolium repens as parent material through natural selection, artificial selection, individual selection and multiple crossbreeding. The summer survival rate was increased by 15 percent. A new cultivar, "Nannong No 1." (Lolium perenne x Festuca arundinacea), was bred by intergeneric crossing with Lolium perenne cv "Manawa" as female parent and Festuca arundinacea as male . It is cold resistant, and tolerates waterlogging and drought. Grazing Tolerant Cultivars of Lucerne with Stool Shoots Based on introduced stoloniferous lucernes, two new cultivars, "Gannong No. 3" and "Gannong No. 2" of Medicago sativa, were bred respectively in semiarid area and alpine area through spot sowing, individual fixed planting and cloning. The proportion of plants with stolons of the former is more than 30 percent, and the proportion of plants with horizontal roots of the latter ranges from 50 to 80 percent (Geng Huazhu, 1995). Polyploid Cultivars Polyploid plants are characterized by eugonic growth, high yield and strong cold and drought resistance, but low seed yield. This feature could be used to increase the yield of vegetative organs. Up to now, heptaploid Triticosecale wittmack cv "Zhangxin 1881" and hexaploid cv "Zhangsi 237" have been bred octoploid. Tetraploid Lolium multiflorum cv "Ganxan No. 1" and "Shangnong" were bred as well. Hybrids These cultivars include Zea mays cv "Jiqing No. 7" (Pa91 X 340), "Longmu No. 3" (GJ60 X GB47-1), "Longmu No. 5" (J38 X GB33), "Liaoqing No. 8" (Liaoyuan No. 1 X Gueiqong), "Huanong No. 1" (Tian 111 X Mexico Euchlaena mexicana inbred line A1), "Xinduo No. 2" (Huangyu 5-5-5 X 7G) and "Zhongyuandan No. 32" etc. These cultivars have significant heterosis. Cultivars of Sorghum bicolor, "Liaosiza No. 1" (S. bicolor male sterile line T X 623A X sugar S. bicolor restorer line 1022) and "Liaosiza No. 2" (S. bicolor sterile line LS3A X sweet S. bicolor restorer line Roma), are waterlogging tolerant, drought tolerant and salinity tolerant. "Wancao No. 2" (Sorghum bicolor x S. sudanense) has low hydrocyanic acid content and is suitable for green use . Pennisetum purpureum (male sterile line Tifa 23A X restorer line Bil 3B-6) is taller and has more tillers. "Mingmu 42" is a fodder cultivar of Saccharum officinarum bred from CO419 (female parent) and PT43-52 (progeny of wild variety, male parent). It is has high yield, high quality and multiple resistance. Cultivars Selected from Wild Plants Puccinellia chinampoensis can grow in salty soil (pH > 9.4, salt content of topsoil 2.0 to 2.5 percent), but native types only germinate where the temperature range is more than 10 ºC. This limits their widespread use. Using four excellent strains and an integrated variety a new cultivar, "Jinong" has been bred. Its germination and yield are improved significantly. Hedysarum laeve and Hedysarum scoparium are excellent pioneer shrubs for wind breaks, sand fixation and fodder. The productivity of wild strains is low. New cultivars, "Zhongcao No. 1" of Hedysarum laeve and "Zhongcao No. 2" of Hedysarum scoparium, were bred through single plant selection, mix selection, strain test, regional testing and production testing. New cultivars retain the excellent features and strong vitality of wild plants and the biomass could be increased by 20 percent. China has a very long history of grass seed production, but seed supply is still a bottleneck for grass and forage production because of the weak breeding work. Despite a set of bases for foundation seed having been set up in the nineteen-eighties, the output of commercial seed is very low. China can only produce seeds of Medicago sativa, Astragalus huangheensis, Melilotus alba, Vicia sativa, Vicia villosa, Leymus chinensis, Puccinellia tenuiflora, Puccinellia chinampoensis, Elymus sibiricus, Elymus nutans, Elymus dahuricus, and Sorghum sudanense to a certain degree. The seeds of Astragalus sinicus are produced and used by farmers themselves, but there are no commercial seeds in China due to the small production scale. The situation of Lolium multiflorum is similar to Astragalus sinicus, the vigour of harvested seeds by farmers is quite low since humid weather and the local government encourages farmers to use the seeds produced in drier areas. Imported seeds are also used in these areas. Seeds of other grasses and forages that cannot be produced commercially include seed of Lolium perenne, Dactylis glomerata, Festuca arundinacea, Trifolium repens, Trifolium pratense and the cold season turf grasses Poa pratensis, Festuca elata, Festuca capillata (Festuca tenuifolia), and Agrostis stolonifera; for these there is almost total dependence on imports. Although large amounts of seed of Zoysia japonica, and Cynodon dactylon can be produced in China, seeds would have to be exported for further selection and cleaning and then reimported for end use because of lack of seed cleaning technology and related equipment. Turf culture in China has developed rapidly at 20 percent annual growth since 1996. Since the demand for grass products from East Asia and within China keeps increasing and the price is steady since 1995, the production of forage products has been promoted, especially based on Medicago sativa. In 2000, the central Chinese government started the "West Development Plan", including returning arable land to pasture and forest on a large scale; this is ongoing. This is strongly increasing the demand for grass, forage and turf seeds . According to statistics, the imported grass seed in 2000 was around 10,000 tons and both forage and turf account for 50 percent. Because of the long term increasing demand for grass seed, China is beginning to invest in their production and since 2001 has set up production bases to promote self-sufficiency. However because turf seed production has high technical requirements, dependence on imports will not be changed in the long term. Zonation of grassland for sustainable ecological and economic development The Zone of Grassland Agro-ecosystems is a multiple-component complex that consists of the environment, flora and fauna, social and economic systems in a geographical area and functions as an ordered and structured integration. Natural conditions vary significantly over the vast territory of China and various grassland types and grassland ecosystems have developed in different regions. In these regions grassland exploitation is characterized by different local social and economic factors. Principle of Division of Economic Zones of Grassland Agro-ecosystems The grassland industry, based on a well-functioning grassland agro-ecosystem, can use both native and introduced forages in a large range of varying ecological environments. Therefore, its adaptability to natural characteristics is wider and more flexible than traditional crop production and forestry. Considering the regional characteristics of grassland industry in relation to natural, social and economic conditions, the zonation for sustainable development is based on the following criteria:
On the basis of the above criteria, China’s grasslands can be divided into seven ecological-economic zones as follows: Zone 1: Inner Mongolia-Ningxia Arid Grasslands, which includes the Ningxia Huizu Autonomous Region, the bulk of the Inner Mongolia Autonomous Region and that part of Hebei Province north of the Great Wall. Zone 2: Northwest Desert Shrublands, which includes Tibet Autonomous Region, the Hexi Corridor of Gansu and Alashan Meng of Inner Mongolia Autonomous Region. Zone 3: Qinghai-Tibet Alpine Shrublands, including Tibet Autonomous Region, Qinghai Province, the southern part of Gansu Province, the western part of Sichuan Province and the northwest of Yunnan Province. Zone 4: Northeast Forests, including Heilongjiang Province, Jilin Province, Liaoning Province and the northeast of Inner Mongolia Autonomous Region. Zone 5: Loess Plateau and Huang-Hai Plain, which covers Shanxi Province, Shandong Province, Henan Province, Beijing and Tianjing Municipalities, the north of Shaanxi Province, the east of Gansu Province, that part of Hebei province to the south of the Great Wall and the parts of Anhui Province and Jiangsu Province to the north of the Huaihe River. Zone 6: Southwest Karst Shrublands, including Guizhou Province, Chongqing Municipality, the east of Sichuan Province, the southeast of Yunnan Province, the bulk of the Guangxi Zhuang Autonomous Region and the west of Hunan Province and Hubei Province. Zone 7: Southwest Evergreen-broadleaf Forests-shrublands, including Zhejiang Province, Jiangxi Province, Fujiang Province, Guangdong Province, Hainan Province, Taiwan Province, Hongkong and Macao, the Sichuan Basin, the south of Shaanxi Province Tianshui Prefecture of Gansu Province, the east part of the Guangxi Zuang Autonomous Rejoin, the parts of Anhui Province and Jiangsu Province to the south of the Huaihe River and the eastern parts of Hubei Province and Hunan Province. Statistical data on local natural and social conditions and agricultural production in each Zone are given in Tables 30 - 33.
Current Grassland Situation and Proposed Strategy for Each Zone Inner Mongolia-Ningxia Arid Grassland Zone This is one of the most important pastoral areas in China. Grassland types change from meadow grasslands to typical grasslands, then to desert grasslands from northeast to southwest, with decreasing precipitation. The environment is fragile due to severe desertification caused by frequent gales, coarse soils, overgrazing and poor management. Deserts and desertified lands make up 11 percent and 18.4 percent respectively of the land of this zone. The rich grassland resources have high primary productivity and stocking capacity. Typical grasslands in Hulun Beir Meng and Jirem Meng in the east of the zone are one of the best grassland areas in China, with annual hay yield and stocking capacity of 900-1500 kg per ha. and 0.7 -1.2 sheep unit per ha, respectively; desert grassland types are in the Ulanqab Meng, on the Ordos Plateau and in the areas to the east of the Helan Mountain Range, with Stipa spp., Salsola collina, Artemisia frigida etc. as dominant species. Annual hay yield and stocking capacity are 400-600 kg per ha. and 0.25-0.40 sheep unit per ha, respectively. Winter grasslands are scarce, only 30 - 60 percent of the warm-season grasslands, so they are heavily grazed and their grazing usually lasts five months, longer than on warm-season grasslands. Significant annual variation in precipitation causes great differences in forage production, which can be as much as four times between a year of good rainfall and a dry one. Crop growing has been expanding to the north, taking over more and more grasslands, resulting in sharpened conflicts in the local society. Nomadic, extensive management still prevails. With rapid growth in livestock numbers and slow development in establishing artificial pastures in past years, the grasslands have deteriorated seriously under heavy grazing. Shortage of pasture and frequent natural disasters cause heavy losses of livestock: loss, sale and domestic consumption by local herders makes up a third each of the total animal production each year. In this zone, crop production should be restricted and development focused on livestock, grassland protection, establishment of artificial pastures and integration of crop production with feedlot operation. Feed processing and mechanization of forage production should have a high priority in development planning. Northwest Desert-shrubland Zone This is the largest of the zones defined in this study; it is in arid and semi-arid desert areas, in most of which annual precipitation is less than 250 mm, with long hours of solar radiation between 2,600-3,400 h/annum. An extremely arid climate, frequent wind and sparse vegetation are features of the fragile environment (Geography Institute, Chinese Academy of Science, 1983). Sand storms often cause serious damage to grassland production. By estimation, desertification and salinization have affected 486,000 km2 and 1,730,700 km2, respectively, which account for 21.6 percent and 47.5 percent of the total affected land in China. There are 676 continental rivers in the zone that are fed by melting snows and glaciers in the Tianshan Mountains, the Kunlun Mountains, the Altay Mountains and the Qilian Mountains. These rivers have played an important role in nourishing the development of local oases agriculture for thousands of years. Nowadays, however, only the Yili, the Ertix and Shule Rivers can maintain their supply to the increasing population in the zone, while the others are seriously short of water. Meanwhile, the area of arable land affected by secondary salinization has reached 14.7 percent and 31.1 percent, respectively, of the total arable lands in Xinjiang and the Hexi Corridor of Gansu (Ren Jizhou and Zhu, 1998). The forage yield (dry matter) of the native grasslands is 300 kg/ha. in mountain areas, and 300-1,200 kg/ha. from sown pastures. It is an indicator of the great potential of grassland productivity of this zone. Livestock production is mainly in the mountains, where serious seasonal imbalance between forage supply and livestock requirement is a major constraint. Very often, in spring, livestock die in large numbers due to fodder shortage. On the other hand, the fodder resources of crop-producing areas in the zone are not used efficiently for there could be a combination of grazing and crop production. As measures of improvement, artificial pastures should be widely and intensively established in mountain areas to protect against natural disasters. Rotational grazing regimes need to be adopted and measures taken to protect water sources. In desert areas the stocking rate should be strictly controlled, while in oases feed and fodder production needs to be expanded. Livestock can be transferred from mountain areas to oases for fattening which would greatly improve the overall production system. Zone of Qinghai-Tibet Alpine Shrublands The population here is the smallest of all zones, while the area of natural grassland is the largest. Due to high altitude, average more than 3,000 m, solar radiation in the zone is 50 percent higher than in neighbouring zones. However, heat resources are less.
Water resources in the zone are unevenly distributed. Annual precipitation is 1,000-2,000 mm, even as high as 3,000- 4,000 mm in some places on the southern slopes of the Himalayas and in the southeast of the Hengduan Mountains. It is only about 50 mm in the Qaidam Basin and the northwest of the Qiangtang Plateau (Geography Institute, Chinese Academy of Science, 1983). Annual precipitation is between 500-700 mm in other areas. Many rivers rise on the Qinghai-Tibet Plateau, which is the area richest in hydraulic energy in China. The rivers are mainly in the southeast. The primary productivity of native natural grasslands is low. Forages from the alpine meadow type are palatable and nutritious, while those from sparse wood and shrub grasslands are of poor quality. Due to the long cold season, windy weather, frequent snow disasters and droughts, the imbalance between fodder supply and livestock requirement is great and so the system has difficulty in resisting the impact of natural disasters. Long-term overgrazing has turned many places on grasslands into Black-Soil-Patches or Sandy Lands (Liu et al., 1999; Ma and Li, 1999; Ma et al., 1999). The off-take of a marketable surplus of animal products in the zone is the lowest in China. Measures for improvement that should be taken include strictly controlling the stocking rate, breed improvement, adopting rotational grazing, establishing artificial pastures and accelerating the development of markets for animal products. Meanwhile, the problems of transport, low adoption of new technology and funding for development should be given a high priority in the agenda. Tourism could be integrated into the traditional grassland industry to take full advantage of the resources of beautiful scenery and native Tibetan culture. The zone is one of the least polluted regions in the world, and thus there is a potential to produce green foods for the increasing demand for such products on the world market. Sustainable development in local society, environment and economy could be realized through organizing a grassland agro-ecosystem that functions well at all its production levels.(Hu Zizhi, 2000)
Northeast Forests Zone The zone is characterized by adequate rainfall but low temperatures. The major grassland types are meadow grassland, typical grassland, alpine meadow and marsh. The dominant species are Leymus chinensis, Stipa baicalensis, Dendranthema maximowiczii and Cinnamomum austro-sinense, with meadows of Leymus chinensis as the most important type. Annual forage yield is 1,000-1,500 kg/ha. (dry matter) and remains quite stable from year to year. The stocking capacity is 1.5-2.0 sheep/ha. Dairy cattle and milk production in this zone takes first place in China and the grassland industry is integrated with local crop production to use local fodder and feed resources such as crop residues and maize, more efficiently. The strategy for development in the zone is to establish large-scale production bases through increased input and establish close co-operation between agricultural sectors for efficient utilization of resources. Ecologically healthy animal products should be the main output of the production bases. Loess Plateau and Huang-Huai-Hai Plain Zone The zone is the area with the longest history of agriculture in China. There are many fine native breeds and rich feed resources. In addition to concentrates, silage and urea-treated maize stover have been widely adopted in recent years in beef feedlots which have become a profitable farm enterprise. To meet the demand for fodder, lucerne (Medicago sativa) cultivation is expanding rapidly. In Gansu and Shandong, farmers grow Medicago sativa (Gannong No. 2 and No. 3, and native or imported cultivars) for hay or selling to the processing company for pellet making. Farmers’ income can be increased by more than 15 percent compared with cereal growing. The climate is of humid or semi-humid monsoon type, with high consistency between rainfall and biologically active accumulated temperature, and is favourable for agriculture. However, the variation in rainfall between years is large and thus drought is a major problem (Hou et al, 1991). Surface and underground water is insufficient to meet agricultural demand. Average runoff per capita is only about 500 m3, only a fifth of the national average (Ren and Bao, 1992). The Loess Plateau is seriously eroded, while the Huang-Huai-Hai Plain is dominated by soils of poor quality for agriculture, such as Shajiang black saline soil and heavy sandy soil. The zone is one of the major areas of forage seed production in China. The forages include Medicago sativa, Melilotus spp., Onobrychis viciifolia, Sorghum sudanese, Astragalus adsurgens, and Zoysia spp. Erosion control and conversion of farmlands to woodlands and pastures should be the major measures on the Loess Plateau for sustainable development. Pasture establishment can be integrated into the planning of small catchment management. In the Huang-Huai-Hai Plain wastelands on sandy river flats and beach areas near the sea can be used to grow pastures for fodder production and soil improvement. Based on established pastures and crop by-products, beef and dairy cattle, sheep and goats can be raised to expand the livestock sector of the local agriculture. Southwest Karst Shrubland Zone There are 48 ethnic minorities and half of the poverty-stricken people in China live in this zone (Research Group of Sustainable Agricultural Development in Karst Regions of China, Chinese Academy of Engineering, 1999). The karst landforms have widely distributed limestone cliffs and bare stone deserts caused by irrational cultivation, overgrazing and deforestation on mountain slopes. It is estimated that the area of stone deserts has quadrupled in the past 50 years in Guizhou and Yunnan Provinces. This trend of land degradation has been accompanied by serious water loss and soil erosion and, as a consequence, general deterioration of the ecological environment (Research Group of Sustainable Agricultural Development in Karst Regions of China, Chinese Academy of Engineering, 1999). Natural grasslands are fragmentarily distributed in mountainous areas and are usually difficult to manage. Moreover there are many poisonous plants, with palatable species accounting for only 30 - 60 percent. Native forage legumes are scarce, but the leguminous shrubs that exist in great number have not yet been utilized. Both overgrazing and under-utilization of local fodder resources exist in the zone. Water and heat resources are rich here, but radiation is inadequate to support plant growth for seed production (Hou et al., 1991). Cereals can be grown but their yield and quality are low. However, local climatic conditions are suitable for making improvement in natural grasslands and establishing artificial pastures by vegetative production (Ren et al., 1999). Sown pastures can have 3-4 cuts, even 6 cuts in some places, annually. Some forages, such as Lolium spp., Stylosanthes spp., Trifolium repens, Trifolium pratense and Dactylis glomerata grow well under local conditions. Annual hay yield is 3,400~4,500 kg/ha. from natural grasslands and 8,000~10,000 kg/ha. from sown pastures; on some it was more than 10,000 kg/ha., with 2,133 ha. of pastures carrying 12,000 sheep that produced 2.5~3.0 kg clean wool each in a year (Jiang et al., 1996 ab). The development of vegetative agriculture and rational utilization of native leguminous shrubs could be a way to realize sustainable development (Ren et al., 1999; Liu et al., 1999). The Central Government can provide funds and policy support to speed up the development on the basis of careful planning for rational utilization of local grassland resources. It is the responsibility of the local governments to allocate land-use rights among farm households as a measure to encourage them to establish artificial pastures on mountain slopes and on other types of wasteland. Southeast Evergreen Broadleaf Forest-shrubland Zone Of all the zones in this study this has the largest population, the most developed economy and the best climatic conditions (Hou et al., 1991) (Tables 31 and 32). Natural grasslands are secondary after tropical and sub-tropical forest is cleared (Yu et al., 1996). Their annual hay yield is 2,000~3,000 kg/ha., but quality is usually poor. Productivity could be increased by 5~8 times if improvement measures are applied (Yang et al., 1997). Traditionally green manure is grown on local farms, so it is easy to establish a new rotation scheme between paddy rice and commercial fodder production in the zone to realize better economic, ecological and social benefits. According to a study by Yang Z.Y. et al. (1997 ab) in Guangdong Province, rotation of Italian ryegrass (Lolium multiflorum) and rice increased the content of organic matter, total N, available N, biomass of micro-organisms and enzyme activity in the soil. These, in turn, increased the yield of early rice and late rice by 10 percent and 7 percent, respectively; furthermore, the annual forage production was worth RMB 15,000. The current area used for forage can be expanded in existing farming systems with available techniques. The processing industry needs to be developed for producing high-quality animal products with high added value. The economic zone of the grassland agro-ecosystem is a kind of integrating system between Grassland Industry, Crop Production and Forestry. It is a multi-component complex of ecosystems in a large geographical area, involving various economic and social activities. The theory of system joining can be used to guide in planning and implementing development programmes in these zones for achieving sustainable economic, social and environmental benefits (Ren and Wan, 1994). System discordance occurs when exchanges between system components or sub-systems are hindered. It usually takes the following forms (Ren and Zhu, 1995):
Experience has proved that realization of system pairing between different zones or between sub-systems in the same zone is the key to solving the problems (Ren and Zhu, 1998). If pairing is successful, the productivity of the systems as a whole can be greatly increased and the results are more likely to be sustainable (Ren and Wan, 1994). China’s population is 1,286,000,000 now and will be 1,385,000,000 by 2010. According to the government plan for the livestock sector, the annual output of meat, eggs and milk should be increased by 19.59 percent, 22.22 percent and 100 percent, respectively, by 2010 in comparison to 2000. Achieving these goals means that the productivity of the grassland industry must be 24.8 animal product units per hectare in 2010, therefore, it also means that measures must be taken to improve existing natural grasslands and establish artificial pastures on a large scale. In addition to pairing between different systems, pairing should be realized between different production levels, so that free flows of material inputs and information can be maintained between the levels. |
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REFERENCES Websites
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The pasture/forage resource profile for China was prepared in 2001 by Prof. Hu Zizhi and Dr. Zhang Degang in Lanzhou, P. R. China, who will undertake periodic updating. [The profile was edited by J.M. Suttie and S.G. Reynolds in April/May 2002 and some livestock data updated in October 2006 by S.G. Reynolds] Click to return to the first page |
