Production efficiency and economic potential of different soil fertility management strategies among groundnut farmers of Kenya

This paper provides the economic evaluation of different soil fertility replenishing technologies (use of inorganic fertilizers, organic manure, and rhizobium inoculant) that were tested during field studies and recommended to groundnut farmers. Data on soil fertility technologies used by households, groundnut yields, and resource use and farm and farmers characteristics were collected through administration of a questionnaire to a sample of 332 farmers from three districts of western Kenya. The data was analyzed to determine whether adoption of the technologies would increase household incomes and production efficiency. Benefits and costs of each technology were computed through the use of budgets. Technical and allocative inefficiencies are investigated by fitting a Cobb-Douglas production function. The technical efficiency of the farmers varied between 0.56 and 0.69 while labor allocative efficiency varied between 0.81 and 0.93. Farmers applying organic fertilizers only were technically more efficient but had lower potential yield compared to farmers who applied inorganic or a combination of organic and inorganic fertilizers. Use of inorganic fertilizers lead to a benefit cost ratio of up to 3:1. Organic manure had the lowest benefit-cost ratio (2.2:1) even when compared with that obtained when farmers did not apply any fertility replenishing input resulting from high cost of labor required to use this technology. There is a high potential for farmers to increase their groundnut yields and incomes by improving on production efficiency and by fertilizing their groundnut farms. Key words: Cost-Benefit ratios, Groundnuts, Kenya, Production efficiency, Production functio

Nutrients limiting soybean (glycine max l) growth in acrisols and ferralsols of western Kenya

Low soybean yields in western Kenya have been attributed to low soil fertility despite much work done on nitrogen (N) and phosphorus (P) nutrition leading to suspicion of other nutrient limitations. To investigate this, a nutrient omission trial was set up in the greenhouse at the University of Eldoret-Kenya to diagnose the nutrients limiting soybean production in Acrisols from Masaba central and Butere sub-Counties, and Ferralsols from Kakamega (Shikhulu and Khwisero sub-locations) and Butula sub-Counties and to assess the effect of liming on soil pH and soybean growth. The experiment was laid out in a completely randomized design with ten treatments viz; positive control (complete), negative control (distilled water), complete with lime, complete with N, minus macronutrients P, potassium (K), calcium (Ca), magnesium (Mg) and sulphur (S) and with, micro-nutrients boron (B), molybdenum (Mo), manganese (Mn), copper (Cu) and zinc (Zn) omitted. Visual deficiency symptoms observed included interveinal leaf yellowing in Mg omission and N addition and dark green leaves in P omission. Nutrients omission resulted in their significantly low concentration in plant tissues than the complete treatment. Significantly (P≤ 0.05) lower shoot dry weights (SDWs) than the complete treatment were obtained in different treatments; omission of K and Mg in Masaba and Shikhulu, Mg in Khwisero, K in Butere and, P, Mg and K in Butula. Nitrogen significantly improved SDWs in soils from Kakamega and Butula. Liming significantly raised soil pH by 9, 13 and 11% from 4.65, 4.91 and 4.99 in soils from Masaba, Butere and Butula respectively and soybean SDWs in soils from Butere. The results show that, poor soybean growth was due to K, Mg and P limitation and low pH in some soils. The results also signify necessity of application of small quantities of N for initial soybean use

Opportunities for Improving Integrated Nutrient Management by Smallhold Farmers in the Central Highlands of Kenya

Integrated Nutrient Management (INM) is an important strategy for soil improvement in smallholder systems of East Africa but successful implementation depends upon identification of opportunities for intervention, which are in turn dependent upon a practical knowledge of farm enterprises and decision making. Surveys addressing soil fertility management were conducted among 190 households in the Central Kenyan Highlands. Farmer-available organic resources were collected during these interviews and later analysed for plant nutrients. The business strategies of 139 retailers of agricultural supplies were assessed through a 23-question survey conducted in 17 districts in the Kenyan highlands. These surveys provided background for identifying promising interventions by farmers to improve soil fertility and for retailers to meet farmers' demands. Soil fertility depletion results from both internal and external flows of nutrients and is often expressed as nutrient deficient patches in farm "outfields". An approach to improving INM separates management practices into four general categories; nutrient recycling, livestock-crop interactions, biological nitrogen fixation and fertiliser use. Fifteen specific farmer practices as candidates for strengthening INM were identified within these four categories. Our findings suggest that farmers in the Central Highlands of Kenya are practising the fundamentals of INM but their efforts are restricted by the availability of organic resources and investment capital.La gestion int\ue9gr\ue9e des \ue9lements nutritifs (INM) est une strat\ue9gie importante pour l\u2019am\ue9lioration des sols dans les syst\ue8mes des petits exploitants de l\u2019Afrique de l\u2019Est mais le succ\ue8s de la mise en application depend de l\u2019identification et opportunit\ue9s d\u2019intervention, qui de retour d\ue9pendent aussi de la connaissance pratique des entreprises des fermes et de la prise de d\ue9cision. Des enqu\ueates adressant la gestion de la fertili\ue9 du sol ont \ue9t\ue9 conduites chez 190 exploitants dans la partie Mantagneuse Centrale du Kenya. Les resources organiques disponibles chez le fermier ont \ue9t\ue9 collect\ue9es pendants deux interviews et plus tard analys\ue9es pour les \ue9lements nutritifs des plantes. Les strat\ue9gies de commerce de 139 d\ue9taillants d\u2019 intrants agricoles ont \ue9t\ue9 \ue9valu\ue9es \ue0 travers une enqu\ue8te de 23 questions conduites dans 17 districts dans les r\ue9gions Mantagneases du Kenya. Ces enqu\ueates ont fourni de donn\ue9es de base pour l\u2019identification des interventions promettantes pour les fermiers pour am\ue9liorer la fertilit\ue9 du sol et pour les d\ue9taillants rencontrer les demandes des fermiers. La d\ue9gradation de la fertilit\ue9 de sol r\ue9sulte des mouvements internes et externes des \ue9l\ue9ments nutritifs et est exprim\ue9e comme spotte d\u2019\ue9lements d\ue9ficients en champs "outfields". Une approche d\u2019am\ue9liorer INM s\ue9pare les pratiques de la gestion en 4 cat\ue9gories principales: recyclement d\u2019\ue9l\ue9ments nutritifs; interaction entre elevage et cultures; la fixation biologique de l\u2019azote et l\u2019utilisation des engrais. Quinze pratiques sp\ue9cifiques des fermiers ont \ue9t\ue9 identifi\ue9es comme candidats pour renforcer l\u2019INM \ue0 l\u2019interieur de ces quatre cat\ue9gories. Nos r\ue9sultats indiquent que les fermiers de la partie montagneuse Centrale du Kenya pratiquent l\u2019essentiel de l\u2019INM mais leurs efforts sont limit\ue9s par la disponibilit\ue9 de resources organiques et du capital d\u2019investissement

Economic Analysis Of Maize-Bean Production Using A Soil Fertility Replenishment Product (Prep-Pac) In Western Kenya

The Phosphate Rock Evaluation Project (PREP) is testing PREP-PAC, a soil fertility replenishment product specifically designed to ameliorate nutrient-depleted "patches" symptomatic of the worst maize-bean intercrops of smallholders' fields in western Kenya. PREP-PAC contains two kg Minjingu rock phosphate, 0.2 kg urea, legume seed, rhizobial seed inoculant, seed adhesive and lime pellet, is assembled and is sold for Ksh. 42 (US 0.76) and is intended for 25 m2 areas. PREP-PAC was tested on 52 farms in four districts of western Kenya during 1998 and compared with adjacent control plots. Farmers selected either a local bush or climbing variety (cv. Flora) of Phaseolus vulgaris as an intercrop with maize (Zea mays). Use of the combined PREP-PAC and climbing bean package increased maize and bean yields by 0.72 and 0.25 t ha-1, respectively (P <0.001), resulting in a 161% return on investment. Total revenue from low pH soils (<5.2) was Ksh. 25 for the control and Ksh. 47 for PREP-PAC. In moderate soil pH (>5.3), total revenue was Ksh. 31 for control and Ksh. 68 for PREP-PAC (P <0.05). Opportunity exists to distribute an affordable soil fertility restoration package among smallhold farmers but the profitability from its use is dependent upon soil conditions and accompanying legume intercrops.Le projet d\u2019\ue9valuation de la roche de phosphate est entrain de tester un produit de restauration (PREP-PAC) de la fertilit\ue9 du sol, particuli\ue8rement d\ue9sign\ue9 pour am\ue9liorer des parcelles \ue9puis\ue9es d\u2019\ue9lements nutritifs, poche sympt\uf4matique des champs de mauvaises association ma\uefs-haricots chez les petits fermiers dans l\u2019Ouest du Kenya. PREP-PAC contient deux kg de roche de phosphate de Minjingu, 0.2 kg d\u2019ur\ue9e, semence de l\ue9gume, semence rhizobiale inoculante, semence adh\ue9sive et pelote de chaux, est assembl\ue9e et command\ue9e \ue0 42 K shs (US 0.76) pour une superfice de 25 m2. Le produit a \ue9t\ue9 test\ue9 sur 52 champs dans 4 districts de l\u2019Ouest du Kenya en 1998 et a \ue9t\ue9 compar\ue9 avec les parcelles temoins adjacents. Les agriculteurs ont choisi entre une vari\ue9t\ue9 volubile et/ou courte de haricot (Phaseolus vulgaris) comme culture d\u2019association avec la ma\uefs (Zea ma\uefs). L\u2019utilisation du PREP-PAC combin\ue9 avec le haricot volubile a augment\ue9 les rendements du ma\uefs et du haricot de 0.72 et 0.25 t ha-1 respectivement (P&lt;0.01), aboutissant \ue0 161% de profit sur l\u2019investissement. Le revenu total de sol au pH bas (&lt;5.2) a \ue9t\ue9 25 Ksh pour la parcelle temoin et 47 Kshs pour PREP-PAC. Dans les sols mod\ue9r\ue9s (&gt;5.3), le revenu total a \ue9t\ue9 Ksh 31 pour le temoin et Ksh 68 pour PREP-PAC (P&lt;0.05). Opportunit\ue9 existe pour offrir un paquet abordable de restoration de la fertilit\ue9 du sol chez les fermiers mais leur rentabilit\ue9 dependra des conditions de sols et de l\ue9gumes accompagnant l\u2019association

Farmers' Perceptions and Adoption of Soil Management Technologies in Western Kenya

A study was conducted to test two hypotheses: that farming conditions significantly influence farmers' perceptions of new agricultural technologies and probability of adoption, and that farmers' perceptions of technology-specific attributes associated with use of new technologies significantly influence adoption decisions. A tobit model analysis of a random sample of sixty farmers revealed farmers' participation in agricultural field days and on-farm trials to be significant at 0.05 level in explaining adoption decisions. Other farm variables that were significant in explaining adoption were farmers' participation in agricultural seminars and workshops (P&lt; 0.01), contact with extension (P&lt;0.05 level) and decision to reduce use level for inorganic fertilisers (P&lt; 0.01). The social status of the farmers was not significant in explaining adoption behaviour. Among the technology-specific attributes, reliability in supply and availability of technologies was significant at 0.05 level in explaining adoption. The impacts of technologies on plants' growth vigour and yield were significant at (P&lt; 0.05). Convenience in use of technologies and labour requirements was not significant in explaining adoption decisions. The results indicate that early technology adopters are likely to be those who participate in local activities that introduce and explain new approaches to soil fertility management.Une \ue9tude a \ue9t\ue9 conduite pour tester deux hypoth\ue8ses: que les conditions de culture influencent significativement les perceptions des agriculteurs pour les nouvelles tecnologies agricoles et la probabit\ue9 d\u2019adoption et que les perceptions des agriculteurs pour les caract\ue9ristiques de technologies sp\ue9cifiques associ\ue9es \ue0 l\u2019utilisation des nouvelles technologies influencent significativement les d\ue9cisions d\u2019adoption. Une analyse du mod\ue8le tobit d\u2019un \ue9chantillon al\ue9atoire de 60 agriculteurs a r\ue9v\ue9l\ue9 que leur participation dans les journ\ue9es champ\ueatres et dans les essais en milieu r\ue9el \ueatait significative \ue0 un niveau de 5% dans l\u2019explication des d\ue9cisions d\u2019adoption. Les autres variables li\ue9s \ue0 la ferme qui \ue9taient significatifs dans l\u2019explication d\u2019adoption \ue9taient: la participation des agriculteurs dans les seminaires et ateliers (P&lt;0.01), contact avec vulgarisateurs 5%, et la d\ue9cision de r\ue9duire le niveau d\u2019utilisation des engrais inorganiques (P&lt;0.001). La situation sociale des agriculteurs n\u2019a pas \ue9t\ue9 significative dans l\u2019explication du mode d\u2019adoption. Parmi les caract\ue9ristiques de technologies sp\ue9cifiques, la fiabilit\ue9 dans l\u2019approvisionnement et la disponibilit\ue9 des technologies \ue9taient significatives \ue0 5% dans l\u2019explication d\u2019adoption. Les impacts de technologies sur la vigueur de la croissance de la plante et du rendement \ue9taient significatifs \ue0 5%. La commodit\ue9 d\u2019utilisation des technologies et des exigences de la main d\u2019oeuvre n\u2019\ue9taient pas significatives dans l\u2019explication de la d\ue9cision d\u2019adoption. Les r\ue9sultats indiquent que les adopteurs en premier des technologies sont ceux qui participent dans les activit\ue9s locales qui introduisent et expliquent les nouvelles approaches de la gestion de la fertilit\ue9 du sol

Effect of Cropping Systems and Nitrogen on Maize and Soybean Yields in Western Kenya

Low fertility in highly weathered and degraded soils largely accounts for poor and unsustainable crop yields in most African countries. Studies further reveal negative nutrient balances in major soil elements such as nitrogen (N) (> 46 kg ha-1 ) and phosphorus (P) (>3 kg ha-1 ) in most countries in sub-Saharan Africa (SSA), with average mining of the former in some parts of western Kenya estimated at up to 112 kg N ha-1 . Productivity of maize and soybean in Kenya, particularly in the western region is generally low, even with application of N, P and potassium (K) fertilizers. The high cost of inorganic fertilizers and decreasing soil productivity demands a reassessment of their use, vis-a-vis, other alternative soil nutrient replenishing technologies. An on-farm experiment was laid down in Bungoma-South, Vihiga, and Teso-North Sub Counties of Bungoma, Vihiga and Busia Counties, respectively of western Kenya to assess the effect of selected cropping systems, N fertilizer and manure on maize and soybean yields. The experiment followed a split-plot design with two factors (cropping systems as the main factor and fertilizer interventions as the sub factor) arranged in a randomized complete block design (RCBD) with three replications. The cropping systems consisted of conventional- that is of maize & soybean intercrop of alternate single rows of each crop, MBILI- planted with maize & soybean intercrop of alternate double rows of each crop- and maize and soybean monocrops. The fertilizer interventions comprised of calcium ammonium nitrate (CAN) and farmyard manure (FYM), both applied at two rates of 30 kg N ha-1 and 75 kg N ha-1 , and without fertilizer (absolute control). The experiment was conducted during two subsequent cropping seasons; short rains between August and December 2011 and long rains occurring between March and August 2012. Results showed that maize yields were significantly larger in both the monocropping (mean yield: 2.0 t ha-1 ) and MBILI systems (mean yield: 1.8 t ha-1 ) compared to conventional farming (mean yield: 1.3 t ha-1 ). For soybeans, significantly larger yields were recorded in the monocropping system (1 t ha-1 ) compared to the MBILI (0.8 t ha-1 ) and conventional (0.6 t ha-1 ) systems. Cropping without fertilizer application resulted to low yields at an average of 1.0 and 0.7 t ha-1 for maize and soybean, respectively. Application of CAN at 30 kg ha-1 resulted to an average maize yield of 2.5, 1.4 and 0.7 t ha-1 in Bungoma-South, Vihiga and Teso-North Sub Counties, respectively. At least maize yields increased when FYM was applied at 30 kg ha-1 by 8 and 14% in Bungoma-South, and Vihiga Sub Counties, respectively, above the yield obtained when CAN was applied at 30 kg ha-1 . Application of FYM at 30 kg ha-1 resulted to similar maize yield as those observed when CAN was applied at the same rate in Teso-North sub county. For Soybean crop, application of either CAN or FYM at 30 kg ha-1 gave very low yields in the entire Sub Counties and in both seasons. Only in Vihiga Sub County where an average of 1.1 t ha-1 was obtained while the other two Sub counties had much less yields. On average, application of either CAN or FYM at 75 kg ha-1 increased maize yields by 29% above those observed when the two fertilizers were applied at 30kg ha-1 . The same trend was observed with soybeans whose yields increased at an average of 26% when either CAN or FYM was applied 75 kg ha-1 . The mean Land Equivalent Ratio (LER) values were greater than 1.0 for the intercropping systems and 1.0 for the monocropping system indicating a yield advantage in intercropping over monocropping