by K.C. Paudel
The mid-hills of Nepal are characterised by complex and labour-intensive farming systems with low returns. About 70% of arable land in the hills can be classed as unirrigated hill slopes (bariland), and only about 30% is irrigated (khetland). Overall cropping intensities on bariland including kitchen gardening, are noted as being more than two to three times the quoted national average of 1.3 and 1.6 as reported by Hagen (1980, cited by Riley, 1991), and Panth and Gautam (1987, cited by Riley, 1991).
Increases in human population in the past twenty years have converted large parts of the forest areas into agricultural land for food production. More intensive cultivation, while maximising the exploitation of soil nutrients in the form of food grains, has meant that less has been put back in return to realise sustainable production.
Soil fertility under the traditional farming system has been maintained by repeated addition of various amounts of organic compost/manure, ranging from three to 21 mt/ha/annum (Heuch, 1986). Large amounts of compost are produced from a mixture of livestock manure, forest leaf-litter and farm waste. However, over-exploitation of forests is limiting the supply of fodder, litter and humus, and unless this trend of diminishing natural resources is checked in time, and the traditional practices of maintaining soil fertility are modified with available or improved technologies, the hill farming systems will no longer remain sustainable. Use of chemical fertilizer to cope with these losses is costly, and is generally impractical for hill farmers in any case, both because of a lack of service infrastructure to provide it, and its cost.
The alternatives are to protect and manage the remaining natural forest resources, to improve locally available technologies for increased forage production and better composting, and to utilize the farmers' own extensive indigenous knowledge of soil fertility maintenance. This chapter deals with the effects of the interaction between forage production and animals upon the replenishment of soil fertility, comparing the effects of traditional and modern approaches to the conditions in the hills of Nepal.
SOIL FERTILITY STATUS IN THE HILLS OF NEPAL
As stated in earlier chapters, Nepal's hill farming systems have been sustained by using traditional practices for maintaining soil fertility. However, overall yields of almost all crops in the hills have decreased over the last twenty years (ADB/HMG(N), 1982) due to a decline in soil fertility. Soil is being lost from the whole land use system through erosion on the one hand, and on the other, fertility is also lost because of intensified cropping patterns, and through other factors such as faulty agricultural practices.
The estimated soil loss per unit area for different land use systems for a typical watershed in the middle mountains of Nepal (see Table 1) reveals that maximum soil loss occurs from degraded range land, and poorly managed sloping terraces.
Table 1: Estimated soil loss from different land use in the mid-hills of Nepal.
|Type of land||Estimated soil loss (mt/ha/annum)|
|Well managed forest land||0 – 10|
|Well managed rice terrace||0 – 10|
|Well manged maize terrace||5 – 15|
|Poorly managed sloping terrace||20 – 100|
|Degraded range land||40 – 200|
Source: Laban (1978, cited by LRMP, 1986)
Results from a soil loss and surface run-off study conducted over different agricultural practices at Kulekhani Watershed for six years, showed a minimum soil loss (1.35 mt/ha/annum) from inward sloping terraces and maximum soil loss (2.24 mt/ha/annum) from outward sloping terraces with contour ridges. (Upadhaya et al, 1991). A similar study conducted in the Eastern Hills at Pakhribas Agricultural Centre to find appropriate crop husbandry practices in the maize/millet system, reported a soil loss of 36.7 mt/ha/annum under farmers' practices of cultivation, and 17 mt/ha/annum under a sole maize crop with minimum tillage and mulch (Sherchan and Chand, 1991). These studies indicated that existing farming practices are also reponsible for soil loss, and require improvement.
Major nutrient (N,P,K) removal by the common cropping patterns in the hills, have been estimated by Sthapit et al (1987) and the data have been presented in Table 6, Chapter 2.
Severe soil loss due to erosion, and nutrient extraction from the soil by cereal cropping, indicate the need for soil conservation as a first step in conjunction with maintaining its fertility status, before planning any programmes to increase productivity. Special attention is needed to check soil loss by improving agricultural practices, and care should be taken to utilize manure efficiently by proper composting and mixing with the soil. Proper management of grazing land in the Phewatal Area of the Western Region was found to increase productivity and decrease erosion in pasture five-fold (Wyatt-Smith, 1982). If this were combined with the addition of adequate amounts of compost, then it ought to be possible to restore and sustain the productivity of arable farm land.
NUTRIENT RECYCLING IN THE HILL AGRICULTURAL SYSTEM
Soil provides the medium for plants to grow, a surface for animals to live on, and food to enable human beings to survive. Forage plants that are grown in the soil are the “inputs” consumed by animals which act as the “factory” to convert plant material into a usable “output”, manure. This can then be put back onto the soil in the form of compost, to replenish fertility, and constitutes the traditional nutrient cycling system of hill agriculture in Nepal. In addition, the use of forest litter. farm waste, and the growing of grain legumes, green manures and bio-fertilizers such as Azolla spp. with minimal use of chemical fertilizers, has also helped to maintain the soil fertility on farm land. Soil fertility maintenance is the combined result of the interactions between plants, animals, and their by-products, a complex but essential component of the whole farming system in Nepal.
Plants (including herbs, shrubs, and trees) protect the soil from the direct effect of rain and wind, and minimise surface run-off by checking top soil erosion, and causing water to slowly percolate into the earth. Their root systems and decomposing plant parts improve the moisture-holding capacity of the soil, and further enhance plant growth. Forage grasses and shrubs that are growing on or around farm land, also help to bind soil particles through their thick root systems, again preventing loss. Natural decay of plant parts including agricultural residues, are mixed with the soil by decomposition processes. Deliberate forest litter collection is a major component for making large amounts of compost when mixed with cattle dung. Mahat (1987) estimated that 2.3mt of litter and manure are used per hectare per year in cultivated land in the hills of Nepal. Khadka and Chand (1987) estimated that 50% of leaf litter was removed from the hill forests annually. Forest litter includes dry leaves, herbs, pine needles, and green foliage that are mixed with animal dung (after bedding or directly) in pits, and which, after decomposition, is transported to the crop land as organic manure.
Though animals have only a limited direct effect on restoring soil fertility, they are the major means by which plant produce is converted to manure through digestion of crop residues and fodder/forage. Addition of their dung helps to improve soil texture, and to decompose litter more easily. With a traditional feeding system, and farm yard manure (FYM) preparation method, an adult large ruminant animal provides about four tonnes of FYM (Table 2) or about 10–13kg of nitrogen per annum. However, six large ruminants are required to provide sufficient FYM for one hectare of farm land under a rice - maize - wheat system for one year (Subedi and Gurung, 1991).
Table 2: Faecal output per animal species with a feeding regime of 20–25 gmDM/kg liveweight/day, and total manure production from the livestock population of the mid-hills.
|Animal species||Faecal output at night |
|Faecal output at day |
|Total faecal output/day |
|Annual faecal output/animal |
|Livestock population in midhills |
|Total annual output |
Source: Khadka and Chand (1987); LRMP (1986)
This production of manure, if used on farm land at a rate of 20 mt/ha. would be sufficient for 1,000,000 hectares of cultivated land in the mid-hills. This is 68% of the total cultivated land area of 1,467,000 hectare (MPFS, 1988), giving a deficit of 32%. However, at present, this deficit is more than doubled, because of inefficient usage. About 46% of manure produced during the day time is lost while the animals are grazing in the forest or on community fallow land, if they are reared under a semi-stall-fed system. Even under an entirely stall-fed system, much of the potential yield is lost through poor housing structure, or inefficient methods of compost preparation.
To compensate for these deficits, forest leaf litter, poultry and rabbit manure are sometimes applied, and legume crops grown with nominal amounts of chemical fertilizer where this is available.
Although collection of forage and leaf litter from the forest has been cited as the ultimate source of plant nutrients, use of the forest for grazing (about 50% of the total area according to Chitrakar, 1990) and leaf-litter collection has depleted forest resources, thereby reducing availability of fodder and intensifying the soil fertility decline. The mechanisms of nutrient transfer under hill farming systems are shown in Figure 1.
METHODS OF MAINTAINING SOIL FERTILITY
Before dealing with soil fertility maintenance, it is necessary to first consider soil conservation. Although very few studies have been made by researchers in Nepal on this topic, farmers are well aware of, and actively attend to the problem. This awareness of the need for soil conservation can be clearly observed in the hills, where entire hillsides are covered with well-terraced farm land.
Construction, maintenance and modification of terraces, drains, irrigation waterways and tunnels, and the use of mulch and cover crops lends support to the concept that farmers are skilled in soil and water conservation (Tamang, 1991). Construction of bamboo and stone check dams in gullies, brushwood dams and gabions in stream sides to protect rice fields from summer floods, and the growing of grasses to stabilize terrace risers are additional evidence of farmers' awareness of soil conservation. Formal engineering practices are costly and so cannot be adopted everywhere, and the development of low-cost appropriate systems for flood prevention and hence soil conservation would be a relevant and worthwhile topic for future research.
The poor and declining fertility status of hill slopes is usually corrected by application of compost and manure. Amounts added very greatly, from 10 to 60 mt/ha, with 15–20 mt/ha the average for the mid-hills (Balogun, 1989; Upreti et al, 1989, cited by Riley, 1991; Shakya et al, 1990, cited by Riley, 1991). Farmers and researchers have identified the maintenance of soil fertility as an important factor that requires more attention in order that present hill farming systems can be sustained. Various projects have developed their own strategies to study and enhance soil fertility in the hills. Lumle in the Western Hills of Nepal has identified three major problems in hill conditions, namely declining soil fertility, shortage of fodder supply, and lack of income generating opportunity. To alleviate these problems Multidisciplinary Research Thrusts have been formed, one of which is concerned with Soil Fertility. The aim is to generate sustainable technologies for maintaining and improving soil fertility, and short and long term objectives have been prioritised (Subedi and Gurung, 1991). Activities under the former include studies on the preparation and use of compost, optimizing the use of chemical fertilizers, identification and use of green manuring plants, and the use of legumes and nitrogen-fixing bacteria in the cropping system.
Longer term strategies include identification of suitable legumes to include in existing cropping patterns, improved livestock management practices to minimise losses of compost, and the development of improved compost preparation and handling techniques.
Fig. 1: Nutrient transfer in the mid-hills of Nepal.
Farmers in Nepal have long been practising various traditional methods to maintain soil fertility. Sthapit et al (1988) and Subedi et al (1989) reported the application of large amounts of farm yard manure and compost, the use of the first spring flood water to trap nutrients leached from forests and village yards, the use of chemical fertilizer, the slicing and burning of terrace risers, the use of short fallow periods, the inclusion of grain legumes in the rotation, mulching with forest litter or crop residues, in-situ manuring, the burning of crop residues and organic matter, and the use of household and kitchen waste. Tamang (1991) additionally reported the use of wood-ash and rice husks in vegetable gardens. Use of green-manuring plants such as Asuro (Adhatoda vasica), and the collection and spreading of dung from community grazing land can also be observed in many areas.
Some of the major practices involving forage production and animal interaction which are widely adopted in the mid-hills of Nepal are now described.
APPLICATION OF FARM YARD MANURE AND COMPOST
The hills of Nepal are reported to have the highest concentration of livestock per unit area of cultivated land anywhere in the world (Chitrakar, 1990) with ten livestock units per family in the mid-hills and fifteen in the high hills. These animals are mostly stall-fed at lower altitudes in high crop intensity areas, and are fed with forage grasses from farm and forest land, and agricultural crop residues such as rice and millet straw. By contrast, in the higher hills animals are mostly open grazed in forests and on fallow land, and relatively few are stall-fed. The dung and urine dropped in the shed, is mixed with left over forage and bedding material, which is collected and stored either in a heap or in a pit. This mixture of dung and organic material makes semi-decomposed compost, which is spread at different rates on crop fields before ploughing, as time permits. Use of such compost adds major and micro nutrient elements to the soil, improves soil structure by retaining moisture, and reduces erosion by providing surface cover. It also has a longer residual effect than artificial fertilizer. The chief disadvantage is that it is a very labour intensive system, requiring many hours of work to transport food from the forest for the animals, and to eventually remove the manure from the homestead to the field. The amount of compost used is different in every individual case, but bariland usually receives between 20 and 28 mt/ha and khetland from nil to 23 mt/ha (Balogun, 1989).
Farmers consider poultry manure to be better than that of sheep and goats, which in turn is regarded as better than that of cattle and buffalo. Existing practices have major drawbacks in terms of quality and nutrient content, which Sherchan and Chand (1991) identified as incomplete decomposition, leaching of nutrients because of poor storage, and loss of urine which is a good source of nitrogen and potassium.
Most farmers use a heap method of composting, and only a few prepare compost in pits. Research has shown significant differences between these methods. Sherchan and Chand (1991), in a study at Pakhribas Agricultural Centre in Eastern Nepal found the heap method to be equally as good as the pit method when composting 50% cow dung mixed with green Banmara (Eupatorium spp.). Lewis (1979, cited by Sthapit et al, 1989) found that the use of pits and store bins gave no advantage over heaps, and that regular turning of compost was not necessary, except when the compost was noted as not decomposing properly. By contrast, an experiment carried out at Lumle revealed that the pit method was superior to the heap method in terms of the nutrient content (Subedi and Gurung, 1991). The quality of the compost is not only determined by the method under which it is produced, but also depends upon the ratio of dung to litter, the type of bedding material used, and the season of composting. These findings were confirmed by an experiment conducted at Lumle to determine the NPK content of different combinations of composting material and the proportion of starter required (Table 3).
Table 3: Comparative nutrient (N,P,K) content of compost prepared from different composting materials.
|S. No.||Composting Materials||Nutrient content (%)||Remarks|
|1.||Maize stubble and Agri lime and 10% dung slurry||0.84||0.057||1.2||4 kg lime after each 30cm layer|
|2.||Weeds and Fingermillet stubble and 10% dung slurry||0.55||0.010||1.2|
|3.||Maize stubble and 10% dung slurry||0.70||0.011||1.1|
|4.||Maize stubble and weeds and complexol fertilizer||1.90||0.132||1.6||2.5 kg complexol for each layer|
|5.||Maize stubble and complexol fertilizer||0.90||0.099||1.7||2.5 kg complexol for each layer|
|6.||Maize stubble and dung slurry and complexol||0.90||0.166||1.3||2.5 kg complexol for each layer|
|7.||Weeds and 10% dung slurry||1.13||0.061||1.2|
|8.||60% FYM and 40% Soyabean and Maize stubble||0.90||0.106||1.5|
|9.||Maize and legume stubble and 1 packet compost maker||1.04||0.043||1.4|
|10.||Cattle dung*||0.3 |
Source: Subedi and Gurung (1991);
* ICAR (1986)
During preparation of the compost, the first turning of composting material was done two weeks after filling and a second turning five weeks after building the heap. Complexol fertilizer (20:20:0) and dung slurry were added during the initial process of decomposition. The compost from maize stubble took eight months to decompose, whereas compost from other residues took six months for full decomposition.
To utilize compost, farmers transport it from the homestead to the field, and either incorporate it immediately, or leave it in the field for a few weeks before ploughing. Which alternative is adopted depends upon the season, the current workload, and the stage of land preparation. Experiments have shown that wet compost incorporated immediately after being carried out into the field resulted in 46% higher grain yield in maize, over compost exposed for seven and fifteen days (Sthapit et al, 1988). Further experimentation at Lumle to confirm this finding, gave non-significant results between the types of compost used and the duration of exposure to the sun. Therefore, this is a topic that requires further research to verify whether existing practices in Nepal where the compost is left in the field before incorporation does or does not result in yield loss in the subsequent crop.
This is the traditional method of manuring agricultural fields, by flocking animals on the field at night, and allowing them to graze in the forest during the day. Under this practice the animals' dung and urine is directly spread on the soil. Generally, buffaloes and cows are kept under temporary shade during the night, but sheep, goats, mules, and donkeys are kept in the open. It is one of the major economic justifications for the continued practice of keeping flocks of sheep and goats under the transhumance system, and their manure is highly valued (Subedi et al, 1989). The practice is done when the fields are fallow, and occurs during the winter (November-March) in the mid-hills. Groups of animals remain on the field for two to three nights depending upon the area to be manured and the size of the flock.
In-situ manuring occurs during the ascent to, and the descent from the alpine pastures. The migratory sheep and goats graze the alpine pastures (above 3000m) between May and September, when the fields of the lower hills contain arable food crops. The flocks descend during September and October, to the agricultural fallow land for winter grazing. The land owners in lower hills, who are in a manure deficit situation, will usually own at least some of the animals in the flock, and so have a claim for their bariland to be manured in-situ. This practice is described in more detail in Chapter 6.
The system operates mostly in the higher hills, and has the advantage of being less labour intensive, cheaper, and of higher plant nutrient value because the urine is not lost. In-situ manuring by sheep has been shown to give a 28.7% higher yield of maize, compared to in-situ manuring by cattle (Subedi and Gurung, 1991). However, this system is becoming less common, because many farmers now grow crops in the winter fallow period, such as wheat, or off-season vegetables. This means that the flocks of sheep are obliged to graze in the forest rather than on crop stubbles, so that additional pressure is being placed on the forest resource at a time when it is particularly vulnerable.
INCLUSION OF GRAIN LEGUMES IN CROP ROTATION
Farmers in the lower valleys on unirrigated flat bariland cultivate black gram (Vigna mungo), soyabean (Glycine max), lentil (Lenus culinaris) and cowpea (Vigna unguiculata), over large areas after the rice or maize crop has been harvested. Soyabean is intercropped on khetland bunds with rice and is also intercropped with the maize/millet system. Mungbean (Vigna radiata), common bean (Phaseolus spp.) and chick pea (Cicer arietinum) are also grown in crop rotations. The symbiotic bacteria of these legumes fix atmospheric nitrogen, and the amount can using from 1–600 kg/ha/year (Sthapit et al, 1988) depending upon species used, vigour of growth and management practice.
The crop residues of these legumes are also either fed to animals or are incorporated into the soil directly. There is ample scope for researchers to explore the degree to which these practices enhance soil fertility.
SLICING TERRACE RISERS
Farmers in the upper hills slice terrace risers once every two to three years for bariland, and every year for khetland. This is done just before ploughing the fields, both to eliminate rodent and insect problems, and also for mixing grasses and new soil from the terrace to improve the soil's texture. The practice has some disadvantages such as loss of soil, high labour cost, and removal of all vegetation cover that could be used as grass forage for animals. However, the practice is continuing in rice fields with flat terraces, where the risk of soil loss is lower, and weed competion would suppress crops if not cultivated.
Because of the lack of year round irrigation, suitable technology, labour availability and manure, and severe grazing pressure, much farm land remains fallow during the winter months after the main summer crop has been harvested. These fallow lands provide a grazing ground for livestock and receive manure for the next season's crop. Farmers at higher altitude may winter fallow only once in every three years, by incorporating grazing facilities for livestock, and changing cropping patterns by interplanting with legumes on a rotational basis to restore soil fertility.
USE OF GREEN MANURING PLANTS
There are many green manuring plants like Adhatoda vasica, Artemisia vulgaris, Walsura trijuga, Sesbania spp., Sapium spp., Albizia spp. and Eupatorium spp. that are used for manuring fields by mixing them into the soil. Various studies on the nutrient content, the effect on crop yields and propagation techniques of green manuring plants have been conducted at Lumle, and some eighteen plant species have been identified as suitable for this purpose (Sthapit et al, 1988). Use of Asuro (Adhatoda vasica) gave between 19% and 49% higher yields of rice compared to the application of 60:30:30kg NPK/ha (Sthapit et al, 1989) (Table 4).
Table 4: Comparative performance of different green manuring crops on rice yields at Lumle.
|Treatment||Grain yield mt/ha at 12%||Straw yield mt/ha at harvest||% yield increase over:|
|Asuro @ 10 mt/ha|
|Compost @ 25 mt/ha||5.1||13.6||27.5||18.6|
|Titepati @ 10 mt/ha|
|Khirro @ 10 mt/ha|
|Dhaincha @ 3.5/ha|
(60:30:30 NPK kg/ha)
Source: Sthapit et al, 1989; Joshi et al, 1990
A similar study conducted with different quantities of green manure at two different sites showed that the highest rice yield was obtained from the areas where Asuro was used as a green manure, followed by Siris (Table 5).
Table 5: Effect of different green manures on yields of rice at Lumle (1450m) and Sera (1250m).
|Treatments||LUMLE (1450m)||SERA (1250m)||Mean|
|Grain yield mt/ha||Wet straw yield mt/ha||Grain yield mt/ha||Wet straw yield mt/ha||Grain yield mt/ha|
|Ricebean @ 60 kg/ha||3.44||16.4||2.89||22.3||3.17|
|Dhaincha @ 60 kg/ha||3.46||17.5||2.23||22.3||2.85|
|Gauras @ 60 kg/ha||3.55||15.5||2.35||11.3||2.95|
|Titepati @ 10 mt/ha||3.33||12.6||2.99||22.7||3.16|
|Asuro @ 10 mt/ha||3.72||19.5||3.81||25.0||3.77|
|Siris @ 10 mt/ha||3.42||18.6||3.73||25.3||3.58|
|Compost @ 10 mt/ha||2.95||13.7||2.62||22.0||2.79|
|Fertilizer @ 60:30:30||3.76||17.3||3.29||20.3||3.53|
Source: Sthapit et al (1991)
Chemical analysis of the leaves of these species has shown them to be of higher plant nutrient content than FYM (Table 6). The green manuring plants are grown chiefly around bariland boundaries, waste land, and forest and farm land. They are applied in the field, either directly by chopping into small pieces, or after use as bedding for livestock in the cattle shed. Because of over exploitation with little attention being paid to their propagation, they are now becoming scarce in the lower hills. Encouragement of propagation would help to produce green manure, thus decreasing the need for FYM and also reducing the pressure on the forest.
Table 6: Nutrient content of various green manuring plants compared with compost in Nepal.
|Plant Species||% composition|
|Asuro (Adhatoda vasica)||4.3||0.9||4.5|
|Titepati (Artemisia vulgaris)||2.1||0.2||4.1|
|Siris (Albizia lebbek)||2.9||0.7||2.6|
|Ankhitare (Walsura trijuga)||2.6||0.1||1.2|
|Dhaincha (Sesbania sp)||1.5||0.3||2.0|
|Khirro (Sapium insigna)||3.0||0.4||2.3|
|Azolla (Asolla pinnata)||4.5||1.6||1.0|
|Banmara (Eupatorium adenophorium)||2.4||0.8||3.9|
|Taramandal (Helianthus spp.)||5.0||0.9||5.2|
Source: Sthapit (1989); Khadka and Chand (1987); Subedi (1989)
Use of chemical fertilizer is not practical in the hills for reasons such as unavailability, lack of awareness among farmers, difficult and costly transportation, and low purchasing power of the hill farming communities. Khadka and Chand (1987) have suggested that blanket recommendations for applications of chemical fertilizer over varied soil types, is also not cost effective. This opinion agrees with the farmers' belief that chemical fertilizer makes the soil “rukho” or poor.
Considering the existing practices, and the farmers' economic situation, no radical changes in soil fertility maintenance are suggested for the present. The improvement of existing practices and resources with the introduction of alternative types of organic fertilizers are seen as the method most likely to succeed at the present time. Some of the possibilities for maintaining and improving soil fertility are addressed below.
No improvement in soil fertility can be contemplated until soil conservation methods are practised. Soils of hills are lost through detrimental agronomic practices such as slicing terrace risers every year, excessive tillage and hoeing in the rainy season, and severe grazing pressure on pasture and forest lands. In order to first check mass soil erosion, improvements to the management of grazing land and degraded forest land are essential. Use of minimum tillage methods, and preventing the practice of slicing tall bariland risers should be adopted to reduce further soil losses. This last practice should be restricted to those areas where soil loss is not a problem, for example flat khetland as discussed above.
Increased Productivity of Forest and Grazing Land
The major reason for declining soil fertility is the need to use the land more intensively because of increasing human population, coupled with a reduction in manure production, so that nutrients extracted by food crops are not adequately replaced. This is the result of a reduction in animal populations in some areas, but is mostly the result of depletion of the animal feed resources from the forest and grass lands, which means that livestock are not realising their full potential the year round.
Productivity of open grassland and forest in the mid-hills is estimated to be able to support only 0.54 and 0.31 livestock units/ha respectively, whereas the present stocking rate is about nine to thirteen times greater than the carrying capacity (Wyatt-Smith, 1982). Therefore, urgent attention must be given to resolving this situation by managing the forest resources properly. Productivity from the forest could be increased by giving priority to fodder tree planting, along with the introduction of improved varieties of grasses and legumes between the trees under silvipastoral management systems.
Improved Animal Management Systems
Large herds or flocks of animals of sub-optimal productivity are not worth much in terms of overall agricultural production, and poor management systems do not help to increase the quantity of animal products. Since 46% of manure is lost in grazing away from the farm, it has been estimated that even if the animal numbers in the hills of Nepal were halved, manure production would remain almost what it is at present, provided that it was collected and utilized properly. Stall-feeding could result in a doubling of the amount of dung collected per animal at present.
Animal populations already overburden the hill farmer, and it is essential to consider complete stall-feeding in order to use the available feed effectively and maximise manure production. The wastage of valuable urine can be prevented and utilized by improving drainage and constructing a store pit at the animal shed. Losses of manure due to rain and sun could be minimised by providing some kind of simple shelter over the compost heap/pit.
Similarly, animal production could be improved by the timely supply of feed and water, without wastage. Straw as a livestock feed can be improved in quality by treatment with urea, and by the practice of ensiling or otherwise preserving the summer surplus of grass and agricultural crop by-products. These could then be consumed during the food scarcity period of winter. Trials to this effect are being carried out under the Fodder Thrust programme previously described.
Improvement in Cropping Practices
In order to supply food grain for a steadily increasing human population from a fixed or limited land resource, improvements to existing farming practices are inevitable. From the soil conservation and fertility standpoint, intercropping of grain legumes within the major cropping systems should be encouraged whenever possible. Similarly, planting grasses and legumes on terrace risers, on farm boundaries and on irrigation bunds should be practised more widely. Legume crops such as cowpea, and crops such as oats and berseem can be grown after the rice is harvested using zero tillage, with broadcasted seed while the ground is still moist. Such practices would provide substantial amounts of forage with a minimum of labour, and render the soil more fertile. Improved crop varieties will give more return over local varieties, particularly where intensive cultivation, and irrigation facilities, or other input supplies are available. However, to achieve this in the hills, government subsidies in addition to technical information may be necessary.
Improvement of Storage and Application of Available FYM
Because of a present lack of awareness of correct preparation methods, manure is often mixed with farm and forest waste in a heap, does not decompose properly, and so is inferior in quality. To alleviate such problems, the pit method of composting should be adopted, and if possible a “starter” such as dung slurry, should be applied to assist proper decomposition. However, possible socio-economic constraints need to be evaluated before recommending these changes to farmers on a wide scale, because of the implied extra labour requirements involved.
Use of Alternate Fertilizer
Additional inputs (fertilizer and technical) are required to increase present productivity. At the stage when supplies of organic manure are insufficient, the use of chemical fertilizer has to be considered. Though costly, and unreliable in supply in the hill districts, the use of chemical fertilizers can supplement FYM in accessible areas. Its careful use, preferably in combination with organic manure, could considerably increase crop yields without causing much deterioration of soil quality.
Use of bio-fertilizers, flood water, and appropriate Rhizobium inoculation of legume seeds may also help to reduce the pressure on the supply of FYM, for which forests are presently being sacrificed to feed animals.
Enhancement of Green Manuring Plants
The present trend of only exploiting green manuring plants should be changed to one of developing their production on a sustainable basis. More than twenty species have been identified that have some sort of role as green manure, but very few are being consciously propagated by farmers. Research into the most suitable species for assessing their quality, and the feasibility of increasing their production should be given high priority.
Institutional Strengthening and Manpower Development
Nepal has a limited number of scientists to investigate problems of soil fertility, and also suffers from insufficient infrastructural and technical laboratory facilities at present. This is hampering the development of improved soil conservation and fertility maintenance methods, through lack of technical information and analytical support services.
Soil fertility in the Nepalese hills is maintained with traditional rather then improved practices. The drawbacks to existing manure production, its utilization, and cultivation practices, limit the potential for increased productivity of food crops.
In this context, the use of farmers' knowledge, and development of improved methods of collection and utilization of available resources will be of the utmost importance in maintaining soil fertility. Scientific forest resource management, improved animal husbandry practices, and maximising animal feed production can all play vital roles in checking soil loss and replenishing soil nutrients.
ADB/HMG(N) (1982). Nepal Agricultural Sector Strategy Study (Vol. II). Detailed Section Review and Analysis. His Majesty's Government of Nepal/Asian Development Bank.
Balogun, P. (1989). A discussion of crop cut estimates of rice, maize and millet yields in the Extension Command Area of Lumle Agricultural Centre. LAC Technical Paper 6. Lumle Agricultural Centre, Kaski, Nepal.
Chitrakar, P.L. (1990). Planning Agriculture and Farmers. Strategy for Nepal. Publ: Mrs G.D. Chitrakar, Kathmandu, Nepal.
Hagen, R. (1980). Nepal. Oxford and IBH, New Delhi, India (cited by Riley, 1991).
Heuch, J.H.R. (1986). The quality of compost applied to farmers field and its relevance to forest management in the mid-hills of Nepal. LAC Technical Paper 11/86. Lumle Agricultural Centre, Kaski, Nepal.
ICAR (1986). Handbook of Agriculture. Indian Council of Agricultural Research, New Delhi, India.
Joshi, K.D., Sthapit, B.R., Pound, B. and Gurung, J. (1990). Research thrust: a multidisciplinary research approach to generate sustainable technologies. LAC Technical Paper 26. Lumle Agricultural Centre, Kaski, Nepal.
Khadka, R.J. and Chand, S.P. (1987). The organic materials: a valuable source of soil nutrients in the Eastern Hills of Nepal. PAC Working Paper 12/87. Pakhribas Agricultural Centre, Dhankuta, Nepal (cited by Subedi and Gurung, 1991).
Laban, P. (1978). Field Measurements on Erosion and Sedimentation in Nepal. Department of Soil Conservation and Watershed Management. FAO/UNDP. IWM/WP/05 (cited by LRMP, 1986).
Lewis, R. (1979). Making and Using Compost. Results of experiments conducted at Pakhribas Agricultural Centre and discussion of methods applicable to Nepali hill farmers. Pakhribas Agricultural Centre, Dhankuta, Nepal (cited by Sthapit et al, 1989).
LRMP (1986). Land Resource Mapping Project. Soil Report. His Majesty's Government of Nepal/Government of Canada.
Mahat, T.B.S. (1987). Forestry-Farming Linkages in the Mountains. ICIMOD Occasional Paper 7, Kathmandu, Nepal.
MPFS (1988). Master Plan for Forestry Sector, Nepal. His Majesty's Government of Nepal/Asian Development Bank/FINNIDA.
Panth, M.P. and Gautam, J.C. (1990). Mountain farming system in Nepal. In: Mountain Agriculture and Crop Genetic Resources. pp 51–68. Oxford and IBH, New Delhi, India (cited by Riley, 1991).
Riley, K.W. (1991). Soil fertility maintenance for sustainable crop production in the mid-hills of Nepal. In: Soil Fertility and Erosion Issues in the Middle Mountains of Nepal pp 83–104. IDRC, Ottawa, Canada.
Shakya, P.B., Upreti, R.P. and Vaidya, S. (1981). Finger millet in Nepal: importance, utilisation and farming systems in a socio-economic context. National Hill Crops Research Programme, Nepal (cited by Riley, 1991).
Sherchan, D.P. and Chand, S.P. (1991). A review of current soil related research activities at Pakhribas Agricultural Centre, Nepal. In: Soil Fertility and Erosion Issues in the Middle Mountains of Nepal pp 83–104. IDRC, Ottawa, Canada.
Sthapit, B.R. (1989). Comparative performance of indigenous green-manuring species on yields of rice. LAC Technical Paper 23/89. Lumle Agricultural Centre, Kaski, Nepal.
Sthapit, B.R., Balogun, P. and Pound, B. (1989). Development of biofertilizer technology in the hills of Nepal: experience of Lumle Agricultural Centre. LAC Technical Paper 22/89. Lumle Agriculture Centre, Kaski, Nepal.
Sthapit, B.R., Gautam, M., Ghale, N., Gurung, D.B., Gurung, G.B., Gurung, J., Gurung, K.J., Paudel, D.R.S. and Subedi, K.D. (1988). The results of a soil fertility thrust Samuhik Bhraman: traditional methods of sustaining crop productivity in the lower hills (300–700m asl): Problems and Potential. LAC Technical Paper 19/88. Lumle Agricultural Centre, Kaski, Nepal.
Sthapit, B.R., Pradhanang, P.M., Subedi, K.D., Kadayat, K.B., Dhital, B.K., Subedi, M., Pandey, R.R., Joshi, K.D., Gurung, J., Vaidya, A., Amatya, L.K. and Jaiswal, J.P. (1991). Lumle rice research report, 1990. LAC Seminar Paper 4/91. Lumle Agriculture Centre, Kaski, Nepal.
Sthapit, B.R. et al (1987). Lumle report on soil fertility research (1986/87). LAC Technical Paper 13/87. Lumle Agricultural Centre, Kaski, Nepal.
Subedi, K.D. (1989). The green manures. Prabidhi Sangalo, Year 3, Vol. 4, 9–12. Publication in Nepali. Lumle Agriculture Centre, Kaski, Nepal.
Subedi, K.D. and Gurung, G. (1991). Soil fertility thrust towards sustainable agriculture: experiences of Lumle Regional Agricultural Research Centre. In: Soil Fertility and Erosion Issues in the Middle Mountains of Nepal pp 61–82. IDRC, Ottawa, Canada.
Subedi, K.D., Gurung, G.B., Paudel, D.R.S., Gurung, K.J., Gurung, D.B. and Gurung, J.B. (1989). Traditional methods of maintaining soil fertility in the mid and high hills (1200–2100m asl) of the Western Development Region of Nepal (Kaski and Lamjung Districts): Problems and Potentials. LAC Working Paper 3/89. Lumle Agricultural Centre, Kaski, Nepal.
Tamang, D. (1991). Indigenous soil fertility management system in the Jhikukhola Watershed. In: Soil Fertility and Erosion Issues in the Middle Mountains of Nepal pp 135–151. IDRC, Ottawa, Canada.
Upadhaya, G.P., Sthapit, M, and Shrestha, K.N. (1991). Run-off and soil loss studies in the Kulekhani Watershed, Nepal. In: Soil Fertility and Erosion Issues in the Middle Mountains of Nepal pp 25–32. IDRC, Ottawa, Canada.
Upreti, R.P., Adhikari, K.N. and Riley, K.W. (1989). Rapid Rural Appraisal trek. Hill Crops, to Solukhumbu, Ramechhap and Dolakha Districts. National Hill Crop Research Programme Travel Report 2/89 (cited by Riley, 1991).
Wyatt-Smith, J. (1982). The agricultural system in the hills of Nepal: the ratio of agriculture to forest land and the problem of animal feed. APROSC Occasional Paper 1. APROSC, Kathmandu, Nepal.