Selected conservation management strategies enhance maize yield stability in the sub-humid tropical agro-ecozone of Upper Eastern Kenya.

Conservation management strategies have been recommended to enhance soil fertility, moisture retention, crop yield, and yield stability in rainfed agriculture. However, there is limited research on yield stability. We evaluated the effect of integrating soil inputs in conservation tillage on yield and yield stability in Meru South, Upper Eastern Kenya, for eleven consecutive cropping seasons. The trial treatments included conservation tillage without soil inputs (Mt), conservation tillage with soil inputs: sole inorganic fertilizer (F), residue + inorganic fertilizer (RF), residue + inorganic fertilizer + manure (RFM), residue + manure + legume Dolichos Lablab L. (RML), residue + Tithonia + manure (RTM), residue + Tithonia + phosphate rock (RTP) and conventional tillage (Control). Conservation tillage with RFM was the best-fit strategy for enhancing yields. There was heterogeneity in yield residual variance. A larger residual variance implied lesser yield stability. Mt treatment had the least yield residual variance of 0.12 Mg ha-2, followed by Ct and RML, 0.15 Mg ha-2, while RTM had the highest yield residual variance of 0.62 Mg ha-2. Contrarily, the most stable treatments had the least average yields. The study indicated a positive influence of incorporating soil inputs in conservation tillage on yield and suggests longer-term research for yield stability.

Influence of soil fertility management technologies on phosphorus fractions, sorption characteristics, and use efficiency in humic Nitisols of Upper Eastern Kenya.

Fractions of phosphorus (P) and its sorption characteristics are affected by different soil fertility (FM) technologies which ultimately affect crop growth and productivity. However, the response of P fractions and sorption characteristics to soil fertility technologies that integrate diverse amendments is still poorly understood in acidic Nitisols. A randomized complete block design was layout in an acidic Nitisol to determine fractions of P, its sorption characteristics and use efficiencies in acidic Nitisols under various FM technologies in field conditions. The use of minimum tillage + maize residue + inorganic fertilizer + goat manure (MTCrGF) had the highest impact on and significantly increased resin-Pi, NaHCO3-Pi, and maximum P sorption (Smax) by 182, 76, and 52 mg P kg-1. Moreover, NaOH-Pi and Smax concentrations were higher under conventional tillage + maize residue + inorganic fertilizer + goat manure (CTCrGF) by 216 mg P kg-1 and 49 mg P kg-1 than the control. MTCrGF and CTCrGF also had the lowest P bonding energy (0.04 L mg-1). CTCrGF had the highest P partial productivity factor (0.093 and 0.140 kg biomass kg-1 P) and P agronomic efficiency (0.080 and 0.073 kg biomass kg-1 P) during the two cropping seasons. The results demonstrate the positive influence of combining multiple P sources on soil P fractions, sorption characteristics, and use efficiencies. Notably, combining either conventional or minimum tillage with maize straw and applying integrated manure and inorganic fertilizer (MTCrGF or CTCrGF) can increase the labile P concentrations and reduce the potential depletion of the non-renewable rock phosphate and the use of inorganic phosphatic fertilizers for agricultural production.

Corrigendum to "Data on the response of Zea Mays L. and soil moisture content to tillage and soil amendments in the sub-humid tropics" Data in Brief 43 (2022) 108381.

[This corrects the article DOI: 10.1016/j.dib.2022.108381.].

Data on the response of Zea Mays L. and soil moisture content to tillage and soil amendments in the sub-humid tropics.

The datasets presented were collected from Chuka and Kandara on-station trials sites in Kenya, conducted for two consecutive years. The main aim of the data collection was to evaluate the soil amendments and tillage influence on Zea Mays L. (maize) crop performance and soil moisture content, as reported by Kiboi et al. [1]. Rainfall data were collected using a manual rain gauge installed within the trial site. A non-destructive sampling of four maize plants next to each other on the centre row in each plot was conducted at the 6th and 10th leaf phase to determine crop growth dynamics. Maize grain and stover were harvested at maturity from net plots of 21 m2 in Chuka and 15 m2 in Kandara. The net plot was derived by excluding the first, the last (guard) rows, and the first and last maize plants in each plot. The net plot approach aimed to minimize the edge effect. For soil moisture content determination, a Polyvinyl Chloride access tube was installed at the centre of each plot. Crop phenology was observed and recorded at 50 and 100% stages per treatment. The datasets presented are supplementary materials to the research article by Kiboi et al. [1]. For statistical analysis, the data were subjected to analysis of variance (ANOVA). The datasets under consideration include daily rainfall, relative chlorophyll content- SPAD values and plant heights, grain yields and stover yields, and periodic soil moisture content.

Adoption of climate-smart agricultural practices among smallholder farmers in Western Kenya: do socioeconomic, institutional, and biophysical factors matter?

Rigorous efforts should be channeled to the current low adoption of climate-smart agricultural practices (CSAPs) in sub-Saharan African countries to improve food production. What determines the adoption level and intensity of CSAPs among smallholder farmers in Kenya? While considering their joint adoption, smallholder farmers' CSAPs adoption determinants were assessed based on a sample size of 300 smallholder farmers in Western Kenya. The CSAPs considered were animal manure, soil water conservation, agroforestry, crop diversification, and crop-livestock integration. A multivariate and ordered probit models were used to assess the determinants of joint adoption of CSAPs in Western Kenya. Both complements and substitutes between CSAPs were established. The multivariate probit analysis revealed that household head's gender, education, age, family size, contact with extension agents, access to weather information, arable land, livestock owned, perceived climate change, infertile soil, and persistent soil erosion influenced CSAPs adoption. The ordered probit model revealed that gender, arable land, livestock owned, soil fertility, and constant soil erosion were crucial determinants of CSAPs adoption. The findings implied that policymakers and relevant stakeholders should consider farmer, institutional, and biophysical factors in upscaling or promoting the adoption of CSAPs.

Communication factors influencing adoption of soil and water conservation technologies in the dry zones of Tharaka-Nithi County, Kenya.

Integrated soil fertility and soil water conservation technologies are possible solutions to the low per capita food production in Sub-Saharan Africa (SSA). Nonetheless, the rate of adoption of these technologies by smallholder farmers has stagnated over the years despite being recommended. This has been attributed to the existence of wide communication gaps among researchers, extension agents, and farmers. Therefore, this study aimed to assess the influence of communication factors on the adoption of the selected technologies among smallholder farmers in the drylands of Tharaka-Nithi County. We used a cross-sectional survey design and collected data using an interview schedule from 400 randomly selected farming households. Binary logistic regression was employed for data analysis. Results showed that accessibility of extension agents after introducing the technology significantly influenced the adoption of combined organic and inorganic fertilizers (p = 0.056), mulch (p = 0.051), and Zai pit (p = 0.058). Similarly, practical orientation significantly influenced the adoption of combined organic and inorganic fertilizers (p = 0.001), mulch (p = 0.010), and Zai pit (p = 0.003). Information repetition significantly influenced the adoption of combined organic and inorganic fertilizers, mulch, and Zai pit at p-value 0.003, 0.001, and 0.001, respectively. Training was essential for mulch and Zai pit technologies at (p = 0.030) and (p = 0.001) respectively, while farmer group membership significantly influenced adoption for combined organic and inorganic fertilizers (p = 0.045) and Zai pit (p = 0.057) technologies. Extension agents should increase their interactions with farmers after the introduction of technologies. Equally use of demonstrations should be encouraged during the dissemination of these technologies among the farmers as they enhance the chances of adoption of the technologies.

Gender-specific determinants of Zai technology use intensity for improved soil water management in the drylands of Upper Eastern Kenya.

Degraded landscapes and soil water stress are long-standing problems to smallholder agriculture in the drylands. Despite the important roles of zai technology in restoring degraded landscapes and improving agricultural productivity, the technology is yet to be adopted to its fullest extent. This can be attributed to gender-linked disparities in agricultural technology utilization. The study, therefore, sought to determine gender-specific determinants of zai technology choice and use-intensity. A multistage sampling technique was employed in randomly selecting 133 female-headed households and 267 male-headed households in Tharaka South sub-county. Quantitative data were collected in a cross-sectional survey using an interviewer-administered questionnaire. Using sex-disaggregated data, Chi-square and t-test statistic were employed to test the statistical significance of dummy and mean value of continuous variables, respectively. Gender specific determinants of zai technology choice and use-intensity were determined using the Heckman-two-step econometric model. The results revealed that, more women farmers (44%) were using zai technology as compared to men (38%). Among women farmers, total cultivated land, access to animal-drawn farm implements, and group membership had an influence on zai technology choice. For men, total cultivated land, group membership and access to extension services positively influenced choice of zai technology. With regard to zai technology use-intensity, total land cultivated, livestock densities, group membership and frequency of trainings on soil and water management were important determinants among women farmers. For men, zai technology use-intensity was determined by total cultivated land and farmers' perceptions on soil erosion. We recommend that, gender-sensitive farm-level policies oriented towards farmer socioeconomic profiles are important deliberations towards choice and intense application of soil and water conservation strategies such as the zai technology.