Application of various high- density organic materials in soil promotes germination and increases nutrient content of wheat

In the arid and semi- arid areas in China, the emergence rate of crops is usually reduced by the undecomposed residues, as the areas are characterized in low temperature and insufficient soil moisture. Thus, an innovative method of straw returning is needed to solve the above problems. In this study, high- density organic matter (HDOM) was made of chopped wheat straw (CWS). The HDOM of wheat straw (HDOM- W) without exogenous addition is one treatment, the HDOM- W containing 10% wheat straw biochar (HDOM- WB) and elemental sulfur (HDOM- WS) in weight categorized as two other treatments. The effects of HDOM on soil and crop growth were systematically evaluated through field in situ and laboratory incubation experiments. The results showed that compared to CWS, wheat germination rate was not significantly decreased in the HDOM- W treatment; the biomass, total N and P concentrations of wheat in HDOM- WS were increased by 137.9%, 137.1%, and 141.8%, respectively (P < 0.05); wheat K concentration in HDOM- WB was significantly increased by 39.7% (P < 0.05). Therefore, application of HDOM in soils can improve seed bed, promote crop growth and increase nutrient content, which eventually elevating soil fertility. Organic materials like crop straws, tree branches, grasses off the farmland, abandoned wood furniture, etc. can be all returned to the field as HDOM to elevate soil fertility. The application of HDOM can be used as an innovative environmental protection technology to tackle the problem of organic waste disposal and sustainably maintain soil quality.