Short-term trade-offs of organic matter management strategies for smallholder farms

Abstract

Organic matter management (OMM) strategies such as farmyard manure (FYM) application, legume integration, crop residue incorporation, and alley cropping are recognized for improving soil fertility and crop productivity. However, studies on yield and economics of a combination of such strategies on smallholder farms are generally scarce, yet an understanding of such can enhance adoption. This study analyzed the yield and gross margins of crops grown with OMM strategies in comparison to those grown under inorganic fertilizer application on smallholder farms. Field experiments with five treatments over two short rainy (SR) and two long rainy (LR) seasons were conducted from January 2018 to February 2020 on 10 smallholder farms. The treatments (T) included T1 (control): the inorganic fertilizer application strategy that involved maize monocrop with 50 kg/ha Diammonium phosphate (DAP) application and the OMM strategies (T2-T5). T2: cowpea-maize-bean-maize rotation; T3: cowpea-maize-bean-maize rotation + 2.5 tons/ha FYM; T4: Faidherbia albida alleys + cowpea-maize-bean-maize rotation; and T5: Faidherbia albida alleys + cowpea-maize-bean-maize rotation + 2.5 tons/ha FYM. The maize in T3-T5 was intercropped with Mucuna pruriens. The results indicate that the grain and residue yields in LR were not significantly different among all treatments. The total variable costs, which included monetarized labor and annualized capital costs for the establishment of F. albida were significantly higher under T1 than in T2-T5 during LR2018 and not significantly different from what was observed under T3-T5 in LR2019. The accumulated revenues and gross margins for the four seasons were not significantly different between T1 and the OMM strategies. We conclude that the integration of OMM strategies can give gross margins similar to the 50 kg/ha DAP application. Further, based on the price sensitivity analysis, we conclude that the smallholder farmers could adopt T3 and T4 as the gross margins under these treatments are less affected by grain price fluctuations than in T1, T2, and T5. Since the smallholder farmers can access the planting materials, we recommend the adoption of T3 and T4 on smallholder farms.

Re-assembling land degradation: toward a nature-society-inclusive soil erosion management strategy. A case of the Rwenzori region, Uganda

“…The land use needs to be changed for example to perennial crops with perennial cover crops that have a self-sowing system." Such a cropping system has been recommended for soil fertility management in a study by Ekyaligonza et al (2022) in the same geographical region. Apart from working on the methods, efforts are also needed on the social and regulatory elements.…”

“…Toward solving such multifaceted constraints, various studies currently emphasize holistic approaches which go beyond taking into account the natural (looking into the triggers and controlling factors) and exploring the socioeconomic, cultural, and political contexts in which soil erosion occurs (Pender et al, 2004;Bewket, 2011;Teshome et al, 2014;Ekyaligonza et al, 2022). This aligns with the assemblage perspective which facilitates the reconceptualizing of an issue to best develop means to tackle it from the hybrid of the social and natural, and the human and nonhuman aspects.…”

The Effects of Integrated Soil Fertility Management Practices in Enhancing Sorghum Yields

“…This decline, from an estimated average yield of 0.95 tons/ha to 0.78 tons/ha, underscores the pressing need for interventions to bolster sorghum production (USDA, 2022). Moreover, the prevailing soil fertility constraints exacerbate this challenge, with most empirical studies focusing on singular soil management practices, leaving knowledge gaps in the implementation of comprehensive soil management techniques (Ekyaligonza et al, 2024). The utilization of green gram (Vigna radiata L.), a popular food and cash crop in Kenya, particularly in the semi-arid regions, further underscores the intricate relationship between crop diversi cation and soil fertility.…”