| Livestock waste fertilization is effective in utilizing and recycling aquaculture waste, while it also plays an important role in the regulating and improving soil nutrient. In order to explore the impacts of application of organic and inorganic fertilizer from chicken manure on soil nitrogen fractions, a field plot experiment with three different N levels was carried out on both of "wheat-maize"and "rape-rice" rotations. It mainly studied dynamic changes of soil total nitrogen, ammonium nitrogen, nitrate nitrogen and soluble organic nitrogen in different growth stages and soil layers.Different organic and inorganic fertilizer effects on soil nitrogen fraction of soil0-60cm in "wheat and maize" crop rotation were as follows:(1) The impacts of different organic and inorganic fertilizer on soil total nitrogen (TN) content of different soil layers in wheat and maize season were different. The organic and inorganic fertilizer had significantly increased soil total nitrogen content in wheat season, and compared to the chemical fertilizer (CF), TN respectively increased20.2%(0-20cm),33.9%(20-40cm) and9.4%(40-60cm); While there was no obvious influence on soil total nitrogen content in maize season compared to CF.(2) With different organic and inorganic fertilizer, soil ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3--N) content varyed with soil layers. Organic and inorganic fertilizer in155kg/hm2(OIF2) and190kg/hm2nitrogen level (OIF3) had effectively increased soil NH4+-N content in wheat season. With the increasing in nitrogen, NO3+-N content of soil0-20cm was gradually reduced. In corn season, organic and inorganic fertilizer of high nitrogen level (OIF3, N225kg/hm2) had improved NH4+-N content of soil0-40cm. And compared with the seedling stage, NH4+-N content in the mature stage was increased35.3%(0-20cm) and20.9%(20-40cm). NO3--N content of OIF1in0-20cm in mature stage was18.38mg/kg1more than in seedling stage, while the NO3--N of OIF3in40-60cm was significantly increased more than CF (increased50.0%).(3) In wheat maturity, the organic and inorganic fertilizer in the N120and155kg/hm2had effectively promoted the increase of soil soluble organic nitrogen content in0-20cm. Compared with the CF, the annual growth rate reached2.45%and13.59%. However, it did not play a significant role in the accumulation of SON in20-60cm. While the organic and inorganic fertilizer in the N155and190kg/hm2level were be significant cumulative effect on SON and compared with CF (increased by10.21-93.72%). In20-60cm, with the increased amount of nitrogen fertilizer, SON content also increased by the application of organic and inorganic fertilizer.(4) The organic and inorganic fertilizer had obviously improved the grain yield of wheat and maize, nitrogen agronomy efficiency (NAE) and partial factor productivity (PFPN). The grain yield with organic and inorganic fertilizer treatments were respectively18.0%and21.1%more than that of CF. The overall performance of NAE and PFPN were that:organic and inorganic fertilizer>CF>OF.Different organic and inorganic fertilizer effects on soil nitrogen composition of soil0-40cm in "rape and rice" crop rotation were as follows:(1) Compared with CF, organic and inorganic fertilizer had effectively improved the soil TN content in rape season in0-40cm soil layer and rice season in0-20cm soil layer. It respectively increased the soil TN content19.9%(0-20cm) and25.3%(20-40cm) more than CF in rape season, and respectively increased soil TN content with64.5%(0-20cm) and5.6%(20-40cm) more than CF in rice season.(2) The utilization of different organic and inorganic fertilizer would generate some impacts on soil NH4+-N and NO3-N content. In rape maturity, it could effectively improve NH4+-N content in the soil; compared with CF, it was able to increase by6.7-14.4%. Along with the increase of nitrogen, there was a tendency of increase of NO3--N content in the soil. However, in rice maturity, with the increasing amount of nitrogen fertilizer, it was not obvious influence on NH4+-N content. The cumulative effect of NO3-N with application of organic and inorganic fertilizer in0-20cm was relatively significant, with increasing rate of20.0-33.3%compared with that in the tillering. Three groups of organic and inorganic fertilizer were respectively22.9%,2.2%and15.7%more than that of CF.(3) In rape season, different organic and inorganic fertilizers in soil of0-20cm were not obviously influence the content of soluble organic nitrogen. While in N150kg/hm2it was particularly notable in the cumulative effect of SON in the soil of the20-40cm; compared with CF, it increase by58.69%. In rice season, the SON contents of different organic and inorganic fertilizers in0-20cm were increased17.69-99.19%more than that of CF. Although there were no significant effect of different organic and inorganic fertilizer on SON content in20-40cm, SON content also presented an increase tendency with increasing amount of nitrogen.(4) Compared with CF, different organic and inorganic fertilizer with different nitrogen level from chicken manure had increased the grain yield, NAE and PFPN of rape and rice, and the average yield rate had increased by20.6%and63.6%respectively. NAE of rape as follows:NAE(OF)>NAE(organic and inorganic fertilizer)>NAE(CF), while NAE of rice as follows:NAE(organic and inorganic fertilizer)>NAE(OF)>NAE(CF); The variation of PFPN were similar with NAE in both rape and rice season. |
