| With people pursuing for the high production, massively using of the chemical fertilizer causes the soil fertility rapid drop specially the soil organic matter. Simultaneously the on-used soil nutrient has been drained so much that the environment has brought the huge pressure. It also reduced crops' resistance ability and the anti-senile ability. The experiment is for the purpose of improving soil ecological environment, enhancing the use efficiency of chemical fertilizer, increasing crops resistance and increasing the crops output, through the straw stalk presses also the field lowly applying fertilizer.The experiments were carried out in Northwest Sci-Tech University of Agriculture and Forestry, Yang ling. The crop planting patters is two crops year; the experiment located the different rates of maize straw ploughed under soil (0kg/hm2, 6000 kg/hm2, 9000 kg/hm2, 12000 kg/hm2 and 15000 kg/hm2). More systematically studies on the growth the flag leaf resistant physiology of stubbing winter wheat,the winter wheat output,the soil carbon-nitrogen and the microbial biomass of soil, obtained as follows has the reference value the conclusion:1 The growth of winter wheat under the different treatmentsThe results show that the more maize straw returning to field, the lower rate of winter wheat seedlings emergence; straw returning is good to tillering in winter, but in spring; the ear formation and the leaf area are from high to low with maize straw increasing, treatment III (9000kg/hm2) is the biggest, processes V (15000kg/hm2) is the smallest; Influenced by maize straw returning, the plant height shows different in different growth period and it can see that plant height is Influence by the tiller and the leaf area.2 The yield of winter wheat under the different treatmentsThe yield trials indicate that, the 1000-grain weight of the wheat is different in the different treatments; the appropriate treatment (9000kg/hm2) is good to the 1000-grain weight of the wheat. Besides the output of processes II (6000kg/hm2) and IV (12000kg/hm2), others reach significance levels, processes III (9000kg/hm2) the output is the highest, processes V (15000kg/hm2) the output is the lowest. The appropriate treatment is the best.3 The abilities of anti-senescence of winter wheat under the different treatments The experiment indicated that treatment III (9000kg/hm2) can remarkably inhibit degradation of the Chla and enhances the Chla/Chlb of wheat flag leaf in the mid and late filling period and inhibit the droping of flag leaf photosynthesis speed; Comparing others, the correlation of photosynthesis speed and the chlorophyll obtains strengthens.With maize straw increasing, the SOD and the soluble protein of winter wheat flag leaf change unimodal, the POD and the MDA of winter wheat flag leaf change single-valleily. The ability of anti-senescence of winter wheat is affected by protective enzymes, especially POD. Processes III the abilities of anti-senescence is the best and the evaluation of membership function is best and the output is highest under this test condition; Processes V is worse.4 The carbon and nitrogen of soil under the different treatmentsThe content of organic matters of each treatment soil has increased compared before sowing, Their order is V > III> IV > II > I.With the straw increasing, the inhibition effect become bigger , then become smaller.This experiment indicate that the effect of treatment III (9000kg/hm2) is best.The straw increasing, the content of alkaline nitrogen of soil is from bigto small; Treatment III (9000kg/hm2) is biggest(5.2mg/kg), Treatment I (0kg/hm2) is smallest(1.9mg/kg). This shows that the straw returning not only play the positive role of the the soil nitrogen supplying, but the the soil nitrogen keeping.the effect of proper straw amount is remarkrable.5 The microbial biomass of soil under the different treatmentsThe appropriate amount of straw returning enhances the microbial biomass-C of soil and can reserve soil carbon for the next stubble crops. The microbial biomass-N of processes III, is better, specially in the later stage. It is good for the carbon-nitrogen of soil and the use of fertilizer.The C/N of microbial biomass is easily affected by maize straw returning than fertilization. The treatments of straw increase the C/N, and change the distribution of microbial. It is favor of the transformation and the mineralization of soil organic matters and enhances the soil fertilizer supplying. The BC/TC of treatment III is the digest, treatment I is the least. The treatment of straw increases the organic matters and available carbon of soil, especially treatment III.In a word, the 9000kg/hm2 of maize straw returning is batter for winter wheat's growth,the abilities of anti-senescence,the output,the soil ecological environment,the carbon and nitrogen level of soil and the microbial biomass of soil.
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