Farm‐scale assessment of maize–pigeonpea productivity in Northern Tanzania

Abstract

Little is known about productivity of smallholder maize–pigeonpea intercropping systems in sub-Saharan Africa. We conducted a survey of 277 farm households in Northern Tanzania to assess socio-economic factors, field management characteristics, and their association with productivity of maize–pigeonpea intercrops. On each farm, crop assessments were focused on a field that the farmer identified as most important for food supply. Variables associated with yields were evaluated using linear regression and regression classification. Biomass production ranged between 1.0 and 16.6 for maize, and between 0.2 and 11.9 t ha−1 for pigeonpea (at maize harvest). The corresponding grain yields ranged between 0.1 and 9.5 for maize, and between 0.1 and 2.1 t ha−1 for pigeonpea. Plant density at harvest, number of years the field had been cultivated, slope, weeding, soil fertility class, fertiliser and manure use were significantly associated with variation in maize grain yield, with interactions among the factors. Fields on flat and gentle slopes with plant density above 24,000 ha−1 had 28% extra yields when fertiliser was applied, while less than 24,000 plants ha−1 yielded 16% extra yield when manure was applied. Plant density at harvest was the key factor associated with pigeonpea yield; fields with densities above 24,000 plants ha−1 yielded an average of 1.4 t ha−1, while less than 24,000 plants ha−1 yielded 0.5 t ha−1. We conclude that performance of intercrops can be enhanced through application of organic and inorganic nutrient sources, and agronomic interventions including weeding, implementing soil conservation measures on steep slopes and optimising plant density.

Contributions of integrated soil fertility management (ISFM) to various sustainable intensification impact domains in Tanzania

“…In sub-humid AEZ, 95% of farmers use improved maize seeds compared to 11% in semi-arid AEZ. High use of improved maize seeds in the sub-humid zone has been reported previously (Kihara et al, 2015;Mugi-Ngenga et al, 2021). Even for manure application, 55% of farmers apply in sub-humid while only 21% apply in semi-arid AEZ.…”

“…Therefore, under these domains, and elsewhere in this publication where relevant, the specific contributions of crop association are presented. Use of crop associations (specifically intercropping) is highly practiced in Central and Northern Tanzania (Mugi-Ngenga et al, 2021) with often high land equivalent ratios relative to monocrops (Woomer et al, 2004;Mhango et al, 2017). 3.…”

The impact of participatory action research and endogenous integrated soil fertility management on farm-gate dietary outputs in northern Tanzania

“…Since the area has an archetypical historic record of agro-advisory services, agricultural potential, and technology deployment, it has been an action research use case for the past 8 years [ 2 ]. Maize-pigeon pea intercrop is the most common farming system in the area where maize is mostly grown for home consumption while pigeon peas are consumed while green but mostly sold to export markets when dry [ 29 , 30 ]. Farmers mostly press sunflower oil for home consumption and sell the seed cakes [ 31 ].…”

“…(1) ). where z = standard normal distribution linked to 95 % confidence interval, p = expected prevalence was set at 50 % which yields the largest sample size to capture wide adoption (86 % manure that include animal droppings, household/farm residues and compost that are transported to the field) as well as low adoption (11 % inorganic fertilizers) [ 30 ]; q = 1- p (expected non-prevalence); e = relative desired precision was set at 5 % to capture low usage; d = design effect was set at 1.3. To account for heterogeneity between the strata due to engagement levels; and r = non-response rate of 5 %.…”

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“…By Esther Mugi-Ngenga and Shamie Zingore S mallholder crop production systems in much of the East African highlands are dominated by maize (Zea mays L.) which is commonly intercropped with grain legumes, mainly pigeonpea (Cajanus cajan (L.) Millsp. ), common bean (Phaseolus vulgaris L.), dolichos lablab (Lablab purpureus (L.) Sweet) and cowpea (Vigna unguiculata (L.) Walp) (Mugi-Ngenga et al, 2021). Beyond direct yield benefits, grain legumes can provide additional ecological benefits that may enhance the productivity of maize in the short and longterm.…”