Research For Effect Of Amendment Of Biochar To Lou Soil On Wheat Yield And Its Mechanism

The research about the effect of biochar on crop yield is the key that solve the doubt whether organic waste resources could be returned into the field as biochar. A pot experiment was conducted in the present study to investigate the effects of application biochar made from apple tree branches(B1) and sawdust(B2) at 5 dosages — 0(CK), 1%(D1), 3%(D3), 5%(D5), and 7%(D7)。 The winter wheat with Lou soil was used as the materials to research the effect of different biochar type and amount on the soil pH, EC, CEC, carbon nitrogen ratio, organic carbon, total nitrogen, ammonium and nitrate nitrogen and rapidly available phosphorus index in two years. At the same time, to explore the variation of microbial carbon and nitrogen and major enzymes of soil. What’s more, to determine the yield and biomass of wheat and the variation of nutrient uptake of aboveground. This aim of this paper is to make a scientific clear answer for the question whether the biochar addition into the field in Guanzhong area in Shaanxi. The results are as follows:(1) Soil pH could be significantly increased as a result of biochar additon. The average of pH was 7.99, it’s increased by 2.86% than control treatment. The increament of sawdust biochar on the soil pH is significantly higher than that of apple branch biochar. The more biochar addition, the greater increament of soil pH.(2) Soil EC could be reduced after apple branch and sawdust biochar addition, and the decrease of on sawdust biochar was higher than apple branch biochar. However, soil EC was decreased with the increase of the biochar addition. in the aeolian sandy soil, the decrease of apple branch on the soil EC is higher than that of sawsust biochar. The average of soil EC was 275.27 us·cm-1, it’s decreased by 49.26% than control treatment.(3) Soil organic carbon could be significantly increased by the apple branch and sawdust biochar addition to soil, the variation trend was CK<D1<D3<D5<D7 with the increase of biochar addition. The soil organic carbon was higher apple branch biochar than sawdust biochar. The average was 20.62 g·kg-1, it’s increased by 76.15% than control treatment(11.71 g·kg-1).(4) The effect of biochar on soil total nitrogen was different with the type and addition of biochar. The total nitrogen could be increased significantly after biochar addition(D1<D3<D5<D7). However, soil total nitrogen was decreased in low increment of apple branch biochar(D1, D3).What’s more, it’s increased in high increment of apple branch, but the level wasn’t significant. While the soil total nitrogen was decreased in sawdust biochar.(5) The soil carbon nitrogen ratio was obviously increased by the biochar addition. The average was 18.88, it’s increased by 106.59% than control treatment(9.14).(6) The soil nitrate nitrogen was no different by two biochar addition. It’s could be decreased by 70.46% in biochar addition in the first season. What’s more, it’s decreased with the increament of biochar. In the second season, the effect of type and increament of biochar on the soil nitrate nitrogen was not significant. Furthermore, the variation rule of the effect of the two biochar on soil ammonium nitrogen was obvious. The average of soil ammonium nitrogen was 14.99 mg·kg-1, it’s decreased by 10.19% than control treatment(16.68 mg·kg-1).(7) The soil rapid available phosphorus was increased by 16.52% in the increament of biochar, the effect of apple branch biochar on soil rapid available phosphorus was better than sawdust biochar. However, the increasing range of soil rapid available phosphorus was obvious in nitrogen and phosphorus fertilizer treatment in the first season, while the increasing range wasn’t obvious in the second season. What’s more, the soil rapid available phosphorus was higher obviously in phosphorus fertilizer treatment than in nitrogen and phosphorus fertilizer treatment.(8) The urease, sucrase, alkaline phosphatase and nitrate reductase activities in soil were increased obviously by biochar addition and the activities were increased with the increament of biochar increased. Furthermore, the soil enzyme activities were higher in awdust biochar than apple branch biochar.(9) The soil microbial carbon and nitrogen was increased with the increament of biochar increased in wheat harvest period, and the result was S2-F2 ?S1-F2 ?S2-F1 ?S1-F1. Furthermore, the soil soil microbial carbon and nitrogen was higher in awdust biochar than apple branch biochar.(10) The wheat yield and biomass were decreased obviously by the sawdust biochar and apple branch biochar in F1 treatment in two years. While in F2 treatment, the wheat yield and biomass were increased then decreased with the increament of biochar increased, what’s more, the soil wheat yield and biomass was higher in apple branch biochar than awdust biochar.(11)The low apple branch biochar addition could be promote the absorption of nitrogen and phosphorus of overground part of wheat, and the promotion effect was better in the first season than in the second season. While the effect was not obvious by sawdust biochar.