Effects Of Different Amounts Of Straw Combined With Inorganic Fertilizer On Wheat Growth And Soil Physical And Chemical Properties

In order to promote straw returning further, to reduce the agricultural ecological environment pollution, to improve soil fertility and productivity, and to promote the development of sustainable agriculture, this study combined field experiment outdoor with test analysis indoor to investigate the influence of different return amounts of corn straw on wheat growth, soil physical and chemical prosperities and nitrogen fertilizers productivity. The experiment aimed to explore the optimal combination of different straw returning amounts with inorganic fertilizer amount, so as to provide scientific theory and practice basis for scientific application and promotion of straw returning in agricultural production. The main results show that:(1) Throughout the growth stage of wheat, the combination of 12000 kg·hm-2 straw returning amount with inorganic fertilizer(N 140 kg·hm-2, P2O5 53 kg·hm-2, K2 O 153 kg·hm-2) is the key combination to reduce the arable soil’s bulk density while increasing its total porosity, saturated hydraulic conductivity and field capacity.(2) Compared to the other combinations, the combination of 12000 kg·hm-2 straw addition amount with inorganic fertilizer(N 140 kg·hm-2, P2O5 53 kg·hm-2, K2 O 153 kg·hm-2) keeps the content of soil organic matter stable and reduced the nitrogen loss from soil profile, which effectively keeps the soil available fertility throughout the growth stage of wheat.(3) In contrast to the other combinations, the combination of 12000 kg·hm-2 straw addition amount with inorganic fertilizer(N 140 kg·hm-2, P2O5 53 kg·hm-2, K2 O 153 kg·hm-2) not only sustains the soil hydrogen peroxidase activity, but also increases soil urease activity, phosphmtase activity and invertase activity in different degrees, which effectively improves the arable soil enzyme activity throughout the growth of wheat.(4) Compared to the other combinations, the combination of 12000 kg·hm-2 straw addition amount with inorganic fertilizer(N 140 kg·hm-2, P2O5 53 kg·hm-2, K2 O 153 kg·hm-2) effectively promotes wheat growth, meanwhile increases wheat yield, nitrogen agronomy efficiency and nitrogen partial factor productivity, which is averagely 27.81%, 325.61% and 22.42% higher than those of the other combinations, respectively.(5) Comprehensively considering the aspects of soil physical and chemical properties improvement, soil enzyme activity sustainment, wheat yield enhancement and nitrogen productivity, the combination of 12000 kg·hm-2 straw addition amount with inorganic fertilizer(N 140 kg·hm-2, P2O5 53 kg·hm-2, K2 O 153 kg·hm-2) is the optimal combination in wheat production.