Documentation of farmer perceptions and site‐specific properties to improve soil management on smallholder farms in Tanzania

Abstract

Identifying sustainable land management practices within smallholder agriculture is a challenge. This is partly driven by the challenge of documenting farmers' perspectives and practices in an integrated manner with site‐specific scientific soil assessment. Smartphone applications such as LandPKS provide new approaches to quantify site‐specific soil degradation and fertility but are untested with African farm management. We surveyed 578 households in rain‐fed maize (Zea mays) production areas of Tanzania using a stratified sampling frame to encompass a wide range of soils and agroecologies. A socio‐economic survey and simultaneous sampling in focal plots documented farmer characteristics, perspectives, and management practices, along with soil properties and crop yields. For a subsample of 58 households, we additionally assessed site‐specific field status with the LandPKS application. Farmer perceptions of change in soil fertility status were consistent with soil properties, for example, a field perceived to be declining in fertility was also likely to have low SOC (1.8% relative to 2.7% for increasing fertility). LandPKS provided additional novel insights into soil limitations such as identifying poor water infiltration areas consistently associated with farmer use of erosion control practices (water infiltration of 4 mm hr−1 vs 20 all other plots). This charts a way forward to address soil fertility and land degradation challenges through the use of smartphone applications to capture site‐specific conditions and farmer concerns as the basis for land management recommendations that are highly relevant and address local conditions.

The Role of Active Soil Carbon in Influencing the Profitability of Fertilizer Use: Empirical Evidence from Smallholder Maize Plots in Tanzania

“…This is in alignment with conclusions from other studies, e.g. Nord & Snapp (2020), who studied soil fertility variability in the same geography. Investments in extension and promotion of integrated use of organic management practices in combination with fertilizer are urgently required if maize based systems are to be productive, which has clear implications for reform of input-based agricultural subsidies (Lal 2006;Adowla et al, 2019).…”

“…This study identifies key soil-related drivers of maize yield and maize yield response to nitrogen fertilizers for Tanzanian smallholders. Our particular emphasis is on organic carbon, a particularly important component of soil fertility (Lal 2006;Nord & Snapp 2020). We use two-wave panel data on farmer-managed plots in 25 maize-producing districts in Tanzania.…”

The role of active soil carbon in influencing the profitability of fertilizer use: Empirical evidence from smallholder maize plots in Tanzania

“…This study identifies key soil‐related drivers of maize yield and maize yield response to nitrogen fertilizers for Tanzanian smallholders. Our particular emphasis is on organic carbon, a particularly important component of soil fertility (Lal, 2006; Nord & Snapp, 2020). We use two‐wave panel data on farmer‐managed plots in 25 maize‐producing districts in Tanzania.…”

“…Tanzania is representative in many ways of the maize‐based farming systems found elsewhere in the region, in terms of its agroecologies and range of biophysical endowments, the predominant production characteristics of its smallholder farmers, and the relatively low levels of market infrastructure development. At the same time, the heterogeneity of production characteristics found within Tanzania's maize growing areas bodes well for its value as a test case for evaluating variability of agronomic responses across key geographical characteristics (Nord & Snapp, 2020).…”

“…Our particular emphasis is on organic carbon, a particularly important component of soil fertility (Lal, 2006;Nord & Snapp, 2020). We use two-wave panel data on farmer-managed plots in 25 maize-producing districts in Tanzania.…”