Investigating the Effect of Wheat Straw Hydrochar on Chemical Properties of a Sandy-Loam Soil

Organic material in agricultural land plays an important role in improving soil fertility. Considering the low amount of this material in Iran's cultivated soil, it seems necessary to find ways to increase it. Hydrochar is one of the most stable organic matters that has attracted many researchers in recent years. The present study aims to investigate the effect of wheat straw hydrochar on some chemical properties of sandy loam soil in a randomized complete block design. For this purpose, from among hydrochar produced at various temperatures (140, 170, 200, and 230 ° C) over four hours, hydrochar produced at 200 ° C is selected as the optimal one due to the highest productivity index of stable organic matter (6.13%). The effect of hydrochar treatments in four levels (0, 2, 5 and 10 g.kg-1 soil) on the chemical properties of a sandy loam soil in lysimeter environments such as organic carbon, total nitrogen, absorbable phosphor, cationic and anionic exchange capacity, acidity, and electrical conductivity is measured. The results show that the addition of wheat straw hydrochar at all levels during the eight months of the experiment results in a significant increase in organic carbon, total nitrogen, absorbable phosphor, cationic exchange capacity, and anionic exchange capacity. It also significantly reduces the electrical conductivity and soil acidity. The results also show that wheat straw hydrochar with 10 g.kg-1 soil as compared to other treatments has the greatest effect on increasing the anionic exchange capacity (2.4 times the control).

Keywords:

cationic exchange capacity , hydrolysis , organic material , soil properties