| Based on National Supervision Base for Loess Soil Fertility and Fertilizer Benefits in YangLing, Shaanxi (1990-2005), the effect of long-term fertilizati on biodiversity of weeds in winter wheat field and winter wheat quality-yields and soil fertility were investigate. The main results obtained are as follows:1. The effect of Weed biodiversity in winter wheat field . There were 16 weed species that belonging to 10 familia and 16 genera among different treatments, which is about 34% of the total number of weed species in winter wheat field in Shaanxi province. The weed biodiversity was decreased with the improvement of soil nutrient status. There are 3-5 weed populations for treatments received NPK and NPK combined with organic materials, meanwhile 6-8 for CK, N, NK and NP treatments. Relative abundance(ra) of weeds among all treatments in this paper ranged from 0 to 73% ,and the ranges of Shannon's diversity indices (H′),Shannon's evenness indices (E)and Margalef's species richness indices (DMG) were 0.2-1.08, 0.05-0.26 and 0.26-1.26, respectively. All these 3 parameters for unbalanced fertilization treatments were higher than that of balanced, and, the differences between unbalanced and balanced fertilization were significant in most case.It was probably due to the different status of available soil nutrients which may had different impacts on the growth of different weeds.2. The effect of wheat grain yield and processing quality.If lack application nitrogen and phosphorus ,thus induce land productivity was decreased by 77.5% and 75.8% for wheat with years continue of planting . Nitrogen and phosphorus were main nutrition elements that affected wheat grain yield .The yield and its CV of treatments without N or P ( CK, N,NK and PK ) were low at 1027.8～1268.1kg/hm2 and high at 38.4%～63.7%,but those of treatments with NP, NPK and NPK combined with organic matter(NP, NPK, SNPK, M1NPK and M2NPK ) were high at 5156.7～5679.4kg/hm2 and low at 22.4%～26.6% respectively.The treatment of CK, NK, PK had higher protein content, gluten content and sedimentation volume than the one of NP, NPK, SNPK, M1NPK and M2NPK. 3) We must pay attention to fertilization in balance in order to get good wheat yield and quality, especially the input of nitrogen and phosphorus fertilizer.3. The effect of soil fertility . 1)Rational application nitrogen and phosphorus or combined with organic materials increased organic matter, total-N and available-N , total-P and available-P of topsoil loess soil and thus increase soil fertility.2) It were different that soil fertility with wheat and maize, If lack application nitrogen and phosphorus ,thus induce land productivity Was decreased with years continue of planting were 66.9% and 45.1% for maize, 77.5% and 75.8% for wheat.3) Coordinate application of organic manure and chemical fertilizers of N,P was the best way to increase contribution to the land productivity it was 93.5%～96.7% for loess soil.
|
PDF Full Text Request