Effects of Fertilizer Micro-dose and In Situ Rain Water Harvesting Technologies on Growth and Yield of Pearl Millet in a Semi-arid Environment

Abstract

Declining soil fertility and low rainfall are key constraints to crop production and are threatening food security in semi-arid areas. Applying inorganic fertilizer at reduced amount (micro-dose) and in situ rainwater harvesting using infiltration pits (IP) or tied ridges (TR) are low-input strategies to cope with these constraints. This work investigates the effect of integrating fertilizer with in situ rainwater harvesting technologies on pearl millet growth, yield and household profitability among Tanzanian smallholder farming communities. Split plot field experiments were conducted from 2015 to 2017 cropping seasons. Flat cultivation (FC) with zero fertilizer application resulted in lowest grain yield ranging from 297 to 453 kg/ha and in a negative net profit (NP). The highest yield of 2202 kg/ha was obtained upon the use of recommended rate under IP, but it resulted in negative NP. Infiltration pits under 25% micro-dose resulted in relative higher grain yield (778–2202 kg/ha) compared to TR (887–1915 kg/ha) and FC (592–1144 kg/ha); despite higher yield, it resulted in negative NP. Tied ridges and FC with micro-dose at 25% of recommended rate had a yield advantage ranging from 537 to 959 kg/ha and 295 to 455 kg/ha, respectively, compared to farmer practices, and both resulted in positive NP. The use of micro-dose at 25% of recommended rate along with TR or FC which gave higher grain yield and NP compared to farmers practice is recommended to resource-poor farmers for improved pearl millet productivity.