The effect of biochar and Wheat Straw on irrigation water productivity in barley

Application of compounds that improve soil moisture retention capacity is one of the strategies to increase water use efficiency in agriculture and solve the problem of water shortage. In many sources, several positive aspects of organic matter application such as biochar as soil modifier and moisture retention capacity improvement have been noted. Biochar is a carbon-rich porous compound produced by pyrolysis of natural organic matter. In the present study, 0% biochar (B1), 2.5% biochar (B2), 5% biochar (B3) and 7.5% biochar (B4), 2.5% wheat straw (W1) and 5% straw (W2) were added to soil with clay loam (S1) texture and sandy loam soil (S2). This pot experiment was performed based on a completely randomized design in three replications and in greenhouse. Biochar application increased water productivity in S1B4 and S2B4 treatments by 138% and 128%, respectively. Straw had a negative effect on agronomic yield and water productivity, so that biological yield in clay loam and sandy loam soil decreased by 82% and 73%, respectively. Water productivity decreased by 41% and 25% in S1W1 and S2W1 treatments. These reductions were statistically significant (P<0.01) and were exacerbated by increased straw in both soil types. The present study showed that biochar application can be a way to improve yield and, consequently, water productivity in agriculture.