Managing soil fertility diversity to enhance resource use efficiencies in smallholder farming systems: a case from Murewa District, Zimbabwe

Abstract

Smallholder farms in sub-Saharan African exhibit substantial heterogeneity in soil fertility, and nutrient resource allocation strategies that address this variability are required to increase nutrient use efficiencies. We applied the Field-scale resource Interactions, use Efficiencies and Long-term soil fertility Development (FIELD) model to explore consequences of various manure and fertilizer application strategies on crop productivity and soil organic carbon (SOC) dynamics on farms varying in resource endowment in a case study village in Murewa District, Zimbabwe. FIELD simulated a rapid decline in SOC and maize yields when native woodlands were cleared for maize cultivation without fertilizer inputs coupled with removal of crop residues. Applications of 10 t manure ha -1 year -1 for 10 years were required to restore maize productivity to the yields attainable under native woodland. Long-term application of manure at 5 and 3 t ha -1 resulted in SOC contents comparable to zones of high and medium soil fertility observed on farms of wealthy cattle owners. Targeting manure application to restore SOC to 50-60% of contents under native woodlands was sufficient to increase productivity to 90% of attainable yields. Short-term increases in crop productivity achieved by reallocating manure to less fertile fields were short-lived on sandy soils. Preventing degradation of the soils under intensive cultivation is difficult, particularly in low input farming systems, and attention should be paid to judicious use of the limited nutrient resources to maintain a degree of soil fertility that supports good crop response to fertilizer application.

Agrobiodiversity conservation enhances food security in subsistence-based farming systems of Eastern Kenya

“…Both lower midland zones had higher crop diversity since farmers sought to maintain diverse crops to mitigate against various uncertainties, especially unpredictable climatic conditions. The crop diversity found represented a high level of species richness which is supported by other studies on agrobiodiversity [33]. Overall (all zones) 38 25 13 The current study recorded low diversity in TUM although the region is on the slope of Mt.…”

“…The household heads were the sole decision makers regarding crops grown where elderly people had high preference for indigenous crops for nutritional and medicinal purposes [24]. Zingore et al [33] recorded similar results in Zimbabwe where elderly smallholder farmers put more emphasis on traditional crop varieties.…”

Factors Affecting Wheat Farmers’ Attitudes toward Organic Farming

“…In contrast to earlier findings, however, there was no meaningful correlation between farm size and the attitudes of farmers toward organic farming. Studies such as Zingore et al [37], Cukur [13], Karki et al [20], Oluwasusi [11], Adebayo and Oladele [34], and Chouichom and Yamao [30] showed a positive correlation, and other studies, for example, Alzaidi et al [22] and Khaledi et al [32], reported a negative correlation between the attitude toward organic farming and farm size.…”

“…Income is associated with the amount of owned land as it is one of the resources for agricultural production. According to Zingore et al [37], wealthier farmers own more land. Some studies such as Oluwasusi [11], Cukur [13], Karki et al [20], Chouichom and Yamao [30], and Adebayo and Oladele [34] show that the attitude toward organic farming has a positive correlation with farm size.…”

The State of Soil Degradation in Sub-Saharan Africa: Baselines, Trajectories, and Solutions

“…Extensive research has been conducted into the broader frameworks of integrated soil fertility management [130][131][132][133][134][135][136][137], conservation agriculture [138][139][140][141][142][143], erosion control [144][145][146][147][148], and improved grazing management [149][150][151]. There is also a wealth of information on the benefits of specific practices such as short legume rotations (improved fallows) [152][153][154][155][156][157][158], agroforestry systems [159][160][161][162][163][164][165], and no-till systems [166][167][168][169][170].…”