Facilitated learning in soil fertility management: assessing potentials of low-external-input technologies in East African farming systems
De Jager, A1., Onduru, D2., Walaga, C3.
1Wageningen University and Research Center, Agricultural Economics Research Institute (LEI), Den Haag, The Netherlands
2ETC- East Africa, Nairobi, Kenya
3Environmental Alert, Kampala, Uganda
ABTRACT
This paper describes the experiences and results of a study conducted in 4 districts of Kenya and Uganda during the period 1997-1999 in which researchers and relevant stakeholders were involved in: (1) participative diagnosis of soil fertility status and management practices, (2) identification, testing and evaluation of low-external-input technologies, (3) formulation of enabling policies and measures at district level. In all 4 research sites and studied farm management systems, the future agricultural productivity is threatened by soil nutrient depletion. The cause of depletion however, differs considerably between the sites. Low and erratic economic returns to agricultural production were observed with a considerable part of these returns based on nutrient mining. Low-External Input technologies (LEIA) alone offer limited opportunities to address the observed problems of soil nutrient depletion in the region. Site-specific combinations of external inputs and LEIA techniques appear to be the most appropriate strategy.
INTRODUCTION
Continued natural resource degradation, increasing levels of poverty, unintended negative impacts of globalisation, low level adoption of technologies, poor governance and marketing infrastructure, and increasing population pressure have been observed to be great impediments to increasing food production in sub-Saharan Africa (McCulloch et al., 1999; Pinstrup-Andersen, 2000). In recent years various publications have addressed the magnitude of resource degradation (Stoorvogel et al., 1993; Van der Pol, 1993; Scherr, 1999; Smaling et al., 1999), and technical solutions to the observed constraints have been proposed (Smaling and Braun, 1996; Mokwunye et al, 1996; Braun et al., 1997). So far, impacts have been rather limited since many of these technical options require relatively high capital investments, need a well-functioning infrastructure and a conducive policy and market environment, all of which are constraining factors in most parts of SSA.
In response to the low success rate, the research community and development organisations are shifting their focus to developing Low External Input Agriculture technologies (LEIA). However, the impacts of LEIA is still a subject of debate with some authors highlighting success stories (Rey et al., 1996; Reijntjes et al., 1992) while others are voicing their inadequacy to meet increasing food demands (Reuler and Prins, 1993; Koning et al., 1998; Blaikie et al., 1997). A new line of thought attempts to combine low and high input technologies in an Integrated Nutrient Management (INM) approach which attempts to maximise the use of local resources and optimise application of external inputs (Smaling et al., 1996; Pretty, 1995).
In the search for INM-practices, LEIA and organic farming practices have hardly been examined systematically. Furthermore, methodologies of study have been anecdotal in nature and lacking active participation of farm households, relevant agricultural players and policy makers who have to satisfy multiple goals. This paper describes the experiences and results of a project in four districts in Kenya and Uganda during the period 1997-1999 in which farmers, extensionists, NGOs, researchers and district policy makers joined hands through a learning process to:
- Diagnose constraints to soil fertility management and opportunities for improving the same;
- Identify, test and evaluate low-external-input technologies; and to
- Formulate enabling policies for soil fertility management with district policy stakeholders.
METHODOLOGY
The study was conducted in four research sites in Kenya and Uganda, two with a high agricultural potential (fertile soils, high and reliable rainfall) and two with a medium to low agricultural potential (low soil fertility, low and unreliable rainfall). LEIA and Conventional farm management, with 14-18 households each, were studied in each site. LEIA management’ was defined as farm households trained in Low-External Input technologies (composting, application of liquid manure etc.) and have applied at least three of those techniques on more than 50% of the cultivated area over a minimum of 3 consecutive years. Conventional management’ was defined as farm households representative of the farming system in the study site, have comparable production resources to that of LEIA group, but not practising any of the defined LEIA techniques.
The nutrient monitoring approach (NUTMON) was used (De Jager et al., 1998, 1999). The approach distinguishes a diagnostic phase and an iterative and participative technology and policy development phase. The diagnosis consisted of the following activities: (1) farm households’ assessment of natural resources using soil maps, transect walks and nutrient flow maps, (2) soil sampling and analysis according farmers soil maps, (3) monthly monitoring using NUTMON questionnaire and (4) analysis. Analysis of the data consisted of (1) analysis of the largely qualitative, farmers’ assessment of natural resource management, (2) analysis of the quantitative nutrient flows using the NUTMON methodology and soil sample results and (3) integration of the two previous steps and discussing results with participating farmers.
Impact assessment of selected LEIA techniques was done through a Participatory Technology Development (PTD) process (Reijntjes et al., 1992) in which technologies were jointly selected, experiments designed, monitored, data collected and evaluated, and results shared with farmers using participatory tools. Based upon the participative diagnosis, the results of the PTD, an inventory of historic developments in the district, and an inventory of the existing and relevant policies in the research sites, draft scenarios for future developments in the research sites were formulated. They were discussed in District policy stakeholders workshops where they were finalised and a prioritised action plan drawn by the policy makers attending the workshop.
RESULTS
Soil and nutrient flow maps enabled farmers to visualise nutrient flows and provided insight into soil nutrient status (Figure 1). The application of the NUTMON model showed that there were marginal differences in nutrient balances between the conventional and LEIA farm management systems (Table 1).
Table 1Nutrient stocks and flows in 4 districts in Kenya and Uganda in the period 1997-1998
Machakos (LPA) / Nyeri(HPA) / Pallisa
(LPA) / Kabarole
(HPA)
CONV / LEIA / CONV / LEIA / CONV / LEIA / CONV / LEIA
N-stock (kg/ha)
N-flow (kg ha-1,yr-1)
N-flow (‰ of stock,yr-1) / 3900
-21
-5 / 6400
-25
-4 / 12200
-99
-8 / 12300
-91
-7 / 3100
-3
-1 / 3000
-4
-1 / 6800
-126
-18 / 8300
-95
-11
P-stock (kg/ha)
P-flow (kg ha-1,yr-1)
P-flow (‰ of stock,yr-1) / 2000
2
1 / 1700
1
1 / 7900
-23
-3 / 8000
-27
-3 / 1000
0
0 / 2500
0
0 / 10300
-70
-7 / 9000
-57
-6
K-stock (kg/ha)
K-flow (kg ha-1,yr-1)
K-flow (‰ of stock,yr-1) / 7800
-9
-1 / 10200
2
0 / 10400
-23
-2 / 15300
18
1 / 6100
2
0 / 6300
1
0 / 7800
-55
-7 / 8400
-7
-1
LPA – Low-Medium Potential Area
HPA – High Potential Area
CONV - Conventional farm management practices
LEIA – Low-external-input farm management practices
The differences between the districts were much more profound. The high potential areas, although different in farming system, both showed a relatively high N, P, K nutrient content of the soil, but also more negative nutrient balances at farm level, especially for N (90–125 kg ha-1 year-1 representing an annual 7-18 ‰ loss of the stock). The latter was mainly due to high erosion, leaching and gaseous losses, despite relative high uses of mineral and organic fertilisers (Figure 1). In Machakos district (Kenya), intensive crop farming on relatively poor soils resultsin negative nutrient balances and an annual decline in N-stock of 5 ‰ at farm level, mainly due to very low levels of external inputs applied. In the low potential areas of Pallisa district (Uganda), keeping of livestock under free-range systems results in nutrients from communal grazing lands being transported into cropping land
The economic performance indicators showed no clear differences between the management systems. However, analysis of labour data showed that LEIA management requires more total farm labour than conventional management. The farms in high potential areas realised on average higher net farm income levels both per farm and per unit area. In Kenya off-farm income is of crucial importance to the total family income, reducing the differences in financial resources between the two areas. When valuing the depleted nutrients against replacement costs, it was observed that huge differences between the districts occur. In Pallisa the replacement cost accounted for 5% of the net farm income while the figure for Nyeri was 11%. In Machakos and Kabarole a considerable proportion of the net farm income was based upon nutrient mining with respective figures of 25-30% and 60-70%. The economic efficiency of crop activities, expressed in gross margins per acre, tended to be slightly higher for the LEIA farm management systems (although not statistically significant).
The technology identification and experimental design exercise resulted in a research plan for on-farm testing in each research district. The results show that significant increases in yield and economic returns can be realised with relative high application levels of compost, but that availability of material and labour inputs soon become limiting factors (Table 2).
Table 2Summarised results from tested low-external input technologies
Nyeri (HPA, Kenya) /- In conventional farms the existing practice of manure and DAP application can be replaced by an application of compost alone without any significant impact on yield and economic returns.
- On farms with LEIA management the addition of liquid manure had no significant impact on yields and economic returns.
- Residual impacts of the treatments in the following season were limited.
- From the economic point of view an application of 8-9 ton of manure/compost per acre is preferred above 17 ton/acre.
Machakos (LPA, Kenya) /
- In both management systems a high application of compost with an additional application of liquid manure gave a significant higher yield and is attractive in economic terms.
- In both management systems a 50% reduction of the high level compost application level showed similar treatment effects at 50% reduced yield levels compared to the high dose treatments.
- On conventional farms the treatment with reduced dose of compost was economically less attractive, while on LEIA farms a slightly higher gross margin was realised but lower returns to labour.
- When the economic impact is expressed in returns per labour day however, the addition of liquid manure was less attractive in both farming systems.
- On farms with conventional management only a very slight residual effect could be observed in maize yield in the following season, while on LEIA farms a strong residual impact was observed.
Kabarole (HPA, Uganda) /
- A high level of manure application had a positive impact on the yield of crops in at least two consecutive cropping seasons.
- Although manure had a considerable impact on yields, the economic returns in two seasons were lower than farmers’ practice when manure is valued at Ush 14000 per ton.
Pallisa (LPA, Uganda) /
- Application of compost, deep tillage and mulch are low-external-input options, which can improve yields in food crops.
- Although the selected low-external-input technologies had a considerable impact on yields, the economic impact (over a 2-season period) at farm level is absent or very limited.
LPA – Low-Medium Potential Area
HPA – High Potential Area
Policy discussion workshops were held in each district with district policy makers from various ministries, researchers, extension staff, NGO-staff, staff from development projects and others. In Table 3 the formulated development scenarios, the conditions required for implementation and a prioritised action plan are presented for Nyeri district as an example.
CONCLUSIONS
In all four research sites and all studied soil nutrient management systems the future agricultural productivity is seriously threatened by soil nutrient depletion. The cause of depletion however differs considerably between the sites. The nutrient status was considerably higher in the high potential areas compared to the low potential areas Soil nutrient analysis revealed that no differences in soil nutrient status could be observed between LEIA and conventional management.
In general rather low and erratic economic returns to agricultural production activities were observed, and moreover a considerable part of these returns are based upon nutrient mining. LEIA farm management resulted in comparable net farm income levels as conventional farm management. In the low potential areas slightly higher income levels were realised with LEIA management. Off-farm income is an increasingly important factor in family income, especially in Kenya. Therefore a targeted exploration of value-added production alternatives (agriculture and non-agriculture) is required to sustain the livelihood in rural areas. Research and development initiatives addressing soil fertility depletion in East Africa should widen its focus beyond the agricultural sector.
Table 3Summarised results from district stakeholders workshop in Nyeri
1 / Establishing efficient and relevant information flows to farmers in a wide variety of technical issues concerning increased sustainable production methods in crops and livestock (much knowledge on the shelve currently not applied)2 / Increase availability of credits and making subsidies available for sustainable production techniques
3 / Establishing organised market structures for inputs and outputs
4 / Better targeted and timely implemented government policy to facilitate agricultural production such as land and price policies
5 / Efficient and large-scale implementation of on-farm integrated nutrient management research
6 / Facilitation of (rural) agro-industry development
7 / Efficient soil analysis available to farmers at affordable prices
8 / General community empowerment through training, information, group formation etc.
9 / Further facilitation of soil and water conservation measures, including water harvesting
10 / General improvement of infrastructure (roads, communications etc.)
Low-external input technologies alone offer limited opportunities to address the observed problems of soil nutrient depletion in the region. Significant increases in yield and economic returns could be realised with relative high application levels of compost, but availability of material and labour inputs then become limiting factors. Appropriate combinations of external inputs and LEIA techniques appear the most appropriate alternative strategy.
Changes in agricultural policies are required to provide sufficient incentives for farmers to undertake short- and long-term investment in soil fertility and soil nutrients. Experiences from this study have shown that policy makers need to be involved, at an early stage, in monitoring research activities geared towards soil nutrient improvement.
ACKNOWLEDGEMENTS
The European Union and the Dutch Ministry of Agriculture, Nature Management and Fisheries are gratefully acknowledged for supporting this research.
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Corresponding Author Contact Information:
A. de Jager, Wageningen University and Research Center, Agricultural Economics Research Institute (LEI), P.O. Box 29703, 2502LS Den Haag, The Netherlands, Phone + 31 70 3358341; Fax + 31 70 3615624;
, ORAL, Engaging diverse stakeholders in support of small farms
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