Impact of biochar on soil hydrodynamics properties, water economy and tomato (Solanum lycopersicum l.) yield in a context of climate change, in semi-arid zone, Senegal.

Abstract

In Senegal, the long period of the dry season, the insufficient amount of water in the rainy season, the water pollution, and the increase in population led to a decrease in freshwater resources and put it under pressure and competition among the users. Inadequate agricultural water management combined with the weak capacity of most Senegalese soils to hold water will lead to more inefficient irrigation water use. This study aims to assess the impact of biochar on tomato yield, growth, and irrigation water use efficiency (IWUE) in sandy-loam soil in West Africa-Senegal. A two growing seasons factorial experiment was conducted with a combination deficit irrigation-biochar from February 2021 to February 2023 with three irrigation levels, i.e. full irrigation (recommended-W0=40L.day-1), 75% of full irrigation (W1=30L.day-1), and 50% of full irrigation (W2=20L.day-1), and three amount of biochar, i.e. 3kg.m-2 (B2), 50%B2 (B1=1.5kg.m-2), and 0%B2 (B0=0 kg.m-2) (control). The application of the irrigation treatment and the measurement of different parameters started 10 days after transplantation. The results showed that the use of biochar over two years of experiment had improved soil bulk density, porosity, and moisture content at field capacity. The growth parameters of tomatoes evolved during the two years of the experiment, going from disparate results in season one to clear significant (P<0.01 and P<0.05) impacts in the second season. The evolution of the yield of tomatoes from growing season one to growing season two was up to 71.5%. Furthermore, our results suggest that biochar treatment, regardless of the amount of irrigated water level, presents a better IWUE than full irrigation without biochar (W0B0). The combination biochar’s lowest irrigation water level (W2B1 or W2B2) can allow water economy up to 50% of full irrigation without compromising the yield.