Conservation tillage and its associated practice such as shifting cultivation has been practised by most farmers as a traditional method. Such a system has helped to restore soil fertility over time. With increasing demand on land the emphasis has moved from resting fallow to continuous and intensive cropping. The no-till programme initiated by Crops Research Institute (CRI) in 1993 has worked in a multidiciplinary team involving researchers from CRI, Ministry of Food and Agriculture (MOFA), Sasakawa Global 2000 (SG 2000) and Monsanto Life Science to develop sustainable practices for adoption by farmers. The method adopted has produced desired results; this has been achieved as a result of increasing farmer participation in the various stages of technology transfer. This has also helped in the development of no-till with Roundup recommendations for use by farmers. 

Results from on-station and on-farms over the year have shown a high net-benefit ranging from 58% - 98% on no-till with Roundup and/Lasso-atrazine over the traditional method of slash and burn. Such encouraging results suggest that research on conservation tillage should continue to develop environmentally friendly technologies for farmers. 

Introduction 

Conservation tillage has been practised by most farmers in the forest and transition zones of Ghana. This practice is associated with shifting cultivation where the vegetation is slashed and burned and the crops are planted with little disturbance to the soil. The land is cultivated for a few years usually 3-4 years and thereafter allowed to revert to fallow for 5-10 years. Fertility restoration depends on the length of fallow, nature of vegetation and the rate at which the soil nutrients are being taken by the fallow vegetation from the subsoil. The slash and burn system as noted by Akobundu (1987), is a tradition that has been handed down from one generation of peasant farmers to another as a practice that is beneficial to crop production. The purpose of burning is to get rid of excess vegetation that will hamper planting and seedling emergence. 

The increasing demand on land in many parts of the country has moved the emphasis on resting fallow to continuous and intensive cropping. In some cases, this has led to many farmers cropping the same piece of land from season to season. Indications are that a time will come when there will be no available forest or secondary vegetation to practice the slash and burn type of land clearing. 

Given that land is a finite resource and that it is being depleted by degradation and non-agricultural uses, it is essential that agricultural practices be adopted that preserves its productive potential. No-till with stubble mulching is therefore becoming more popular with farmers in the forest and transitional areas as an effective means of soil and water conservation for sustainable agricultural production on a given piece of land. Farmers, researchers and extensionists through conservation tillage and residue management to conserve soil fertility and increase soil productivity have employed various chemicals and cultural practices. However, to add meaning to the adoption of no-till with stubble mulching as a sustainable stable alternative to the shifting cultivation and its associated slash and burn type of land clearing, Monsanto Life Sciences assisted the Crops Research Institute (CRI) in Ghana to evaluate the efficacy of the powder formulation of Roundup Dry (Sodium salt; contains 420g glyphosate/kg). 

The objective of the conservation-tillage programme has been to help farmers to obtain the maximum benefit from their investment in the no-till through: 

• Elimination of slash and burn
• Increase in organic matter content of the soil surface
• Eliminate destruction of soil structure.

Methodology 

Information generation 

The method employed by the no-till programme is a multidisciplinary team work and a farmer oriented approach which involves researchers from the crops Research Institute (CRI), the Ministry of Food and Agriculture (MoFA) in collaboration with Monsanto Life Science and the Sasakawa Global 2000. 

The team gathers information through surveys, farm visits and interaction with farmers to elicit their problems, interests and needs in relation to conservation practices. The series of trials started in 1993 were to develop farmer recommendations for the Roundup Dry in the no-till system. The trials started with evaluations at the research stations of the C.R.I which were then followed with on-farm testing to validate the results obtained at the station and also to ease the transfer of the technology developed for adoption by farmers. 

On-farm verification studies 

With the indications of either 2 or 3 sachets of Roundup Dry (1 sachet = 130g)/15 l water offering good pre plant weed control, it became necessary to verify the rates under the farmer circumstance. On-farm verification studies were therefore conducted across the major agroecological zones. The trials were managed by the farmers concerned with the field staff of the MoFA helping in the data collection. 

Work plan 

Pre-season Training 

The yearly activities start with pre-season training of farmers and frontline staff of MoFA. During this training, participants are taken through the various aspects of the field activities such as: 

• Sprayer calibration
• Time and rate of herbicide application
• Follow-up weed control

Demonstration 

The next stage of the programme involves field demonstration. These are multi located fields usually sited at strategic points showing the promising no-till technologies. Plot sizes usually ranges between half acre to one acre. Farmers are involved from site selection through herbicide application, planting, monitoring, data collection and harvesting. 

Field days: 

Field days are often organised during the critical stages of the technology dissemination for researchers and extensionists to interact with a large number of farmers. This helps to solicit farmers’ views and create a forum where they can receive advice on the no-till programme. During the field days the co-operating farmer is the key actor and the researchers and extension staff support him. During such fora, input sellers are also present. 

Field tours 

Regular farm visits are organised during which farmers are given enough time to comment and express their opinion frankly; this has helped to create equal partnership among the stakeholders. 

Workshops and seminars 

These are organised occasionally for researchers, extension staff and farmers to exchange ideas on the progress made. 

Fact sheets 

These are prepared by researchers and extension staff and distribute to farmers and frontline staff to serve as guide on the technologies generated. 

Results 

The progression of work at the station and farmers fields (tables 1-6) indicates different experiments carried out over the years to develop farmer recommendations of the Roundup in no-till system. The field trials started with evaluations at the research stations of the CRI (Tables 1 and 2). 

Table 1. Percent+ weed control score (28 days after treatment) at seven locations. 
 

+ 100 % = Complete control relative to vegetation outside experimental plots.  * Increase in % weed control  Source: Ghana Grains Development Project (GGDP) Annual Report, 1993

The trial report indicates that at sites where grasses e.g. Cynodon dactylon, Rottboellia cochinchinensis etc. dominated, weed control was very high and there were no significant differences between rates. However as the broadleaf weed population increased, the required rates of Roundup Dry increased. The general observation was that increasing the rate of application resulted in increasing weed control. Looking at the increase in percent weed control with increasing rates of application, it appeared that not more than 3 sachets/15 lt. water would be needed for adequate weed control (shaded portion of table 1). Several other tests were conducted at the research sites in the various agroecological zones with very promising results on the efficacy of the Roundup Dry formulation (table 2). 

Table 2: Weed count/m² at Mampong (Forest area), Percent weed control at Golokwati (Coastal savannah) and weed weight/m² at Ejura (Forest-savannah transition) 
 

Source: GGDP. Annual Report. 1994 (WAP = Weeks after planting)

The weed counts percent weed control and weed weights all indicated that the Roundup Dry could be a reliable product in the no-till system and that either 2 or 3 sachets could be used. Some on-farm results are presented below: 

Table 3: Weeds/m² and grain yield of maize from Roundup Dry study in the Guinea savannah zone. 
 

Source: GGDP. Annual Report, 1994

Table 4 Effect of pre plant weed control using Roundup Dry on maize yield in the Eastern region (forest ecology) of Ghana. 

Source: GGDP. Annual Report, 1995

The farmer practice in Table 3 was basically hoe ploughing and in Table 4, was slash and burn. Similar to the results from the research stations, the on-farm verification studies also indicated that either 2 or 3 sachets of Roundup in 15 l water could be used. 

Table 5 Effects of chemical and manual weed control methods of Imperata cylindrica on maize yields - coastal savannah, 1991. 
 

Source: GGDP Annual Report 1992

This indicates that work on conservation tillage has been going on for some time now. This has helped to identify suitable and economic methods of weed control, moisture conservation and increase in soil productivity. The collaborative no-till programme has thus helped the soil conservation work to be more focused. 

Table 6 Grain yield, variable cost of production and net benefit maize from Roundup dry.1997 experimental test plots (ETP,s). 
 

Table 7. Changes in area planted to maize by Asuoyeboa seed grower from 1994-97 under no-till. 
 

Table 6. shows that the percentage benefit in terms of cash could go from 58% to 98% if farmers use no-till with herbicides. This excludes the additional benefit on soil conservation. This trend is also shown in Table 7, where seed growers by adopting this technology have been able to increase their farm sizes and thus their business. 
 

General observations 

The no-till collaborative programme has produced a lot of impact on participatory technology generation and adoption by farmers. Among the important achievements are: 

• The no-till with Roundup technology has been adopted and is being used in Sasakawa Global 2000 supported experimental test plots (ETP’s), Farmers’ production plots (FPP) and Village improvement projects (VIP).

• Over 60% of C.R.I station trial plots are under no-till with Roundup.

• Farmer involvement has been very high. This means that field staff and researchers treat farmers as equal partners. This has helped to improve communication and mutual trust among stakeholders.

Future prospects 

Following the encouraging results from on-farm trials and demonstrations and the interest shown by small scale farmers the no-till programme hopes to explore and extend the technology to medium and large scale farmers as well as seed growers who have shown interest and are using the technology. 

Since technology generation is dynamic and evolving, research will continue to backstop the programme. This will help facilitate the development of environmentally friendly technologies for farmers. 
 

Summary and Conclusions 

The methodology used has produced desired impact on no-till technology transfer. Increase in farmer participation has resulted in high rate of no-till technology adoption. The no-till programme is helping farmers to expand their farm sizes with little damage to the soil. The no-till programme will aim at developing environmentally friendly technology for farmers. 
 

References 
 

Akobundu, I.O., 1987: Weed Science in the Tropics. Principles and Practices. John Wiley and sons Ltd. chister Ghana Grains Development (GGDP). Annual reports. 1992,1993, 1994 and 1995