| Plenty of organic matter and essential element for plants such as nitrogen, phosphorus, potassium and other trace element are contained in crop straw. Straw returned to the field could improve soil fertility and soil moisture conservation, stimulate the growth and development of crops and finally increases grain yields. Thus straw returned to the field is an inevitable trend of modern agricultural development. Huaibei plain is a wheat/corn two crops one-year area where is mainly composed by lime concretion black soil. Wheat straw returned to the field affect maize emergence because of the compact texture, easily drought and flooding, and short workable period of soil, at the same time, the amount of organic fertilizer was insufficient, and undeveloped garicultural machinery, all these result in lower returning rates. Based on the problems existing in production, the present study was conducted to investigate physiological and ecological effects of wheat and maize straw returned to the field and fertilizer on summer maize with a series of experiments in two years. The suitable method of wheat straw utilization were discussed, and suitable sowing machinery which could meet the requirement of maize precision sowing under the condition of wheat straw returned in lime concretion black soil region. Thus to provide theoretical and practical basis for high-efficiency cultivation of realizition mechanization of wheat straw directly returning and integration of maize precision sowing and subsoiler with fertilizer spreader. The main contents and results are as follows:1. The physiological and ecological effects of wheat straw mulching in maize field and maize straw burrying in wheat field with fertilizer on maize were studied using compact type maize variety Zhendan 958. The result suggest that, under the condition of directly sowing maize with rotation seeder of SGTNB—200Z4A8 from"Ya'ao in Xi'an"which was drived by X850 tractor with 75 power of from"Dongfanghong"after the stubble breaking of wheat straw, there was no significant difference in sowing quality between wheat/maize straw returned in two seasons and control in sowing quality of maize, while there was significant difference in emergence number and emergence rate between them. The high yield population of even and strong after thinning and final seedling. To compared with control, the plant height, dry weight, leaf area and root activity of maize seedlings of wheat/maize straw returned in two seasons without fertilizer were significantly lower, so as the leaf area index of population and leaf net photosynthetic rate after silking stage, thus reduced the accumulation of dry matter, the uptake of N,P and K and the logding resistance, finally decreased significantly in yield and economic benefit. Contrary to wheat/maize straw returned in two seasons without fertilizer, the plant height, dry weight, leaf area and root activity of maize seedllings of wheat/maize straw returned in two seasons with fertilizer were significantly increased compared with control, so as the leaf area index of population and leaf net photosynthetic rate after silking stage, thus enhanced the accumulation of dry matter, the uptake of N,P and K and the logding resistance, finally increased significantly in yield and economic benefit. Furthermore, grain yield of wheat/maize straw returned in two seasons was sigher than that of wheat/maize straw returned in single seasons with fertilizer.2. With directly cover as control, the physiological and ecological effects of two treatments of wheat straw such as grinding cover(add straw smushing device in wheat harvester) and stubbling cover(treat stubble with stubble chopper) on maize. The result indicated that, under the condition of directly sowing maize with rotation seeder of SGTNB—200Z4A8 from"Ya'ao in Xi'an"which was drived by X850 tractor with 75 power of from"Dongfanghong"after the stubble breaking of wheat straw, the difference among different treatments in sowing quality was inconspicuousness while the emergence number and emergence rate of grinding cover and stubbling cover were significant higher than that of control. The high yield population of even and strong after thinning and final seedling. To compared with control, the plant height, dry weight, leaf area and root activity of maize seedlings of grinding cover and stubbling cover were significantly higher, so as the leaf area index of population and leaf net photosynthetic rate after silking stage, thus enhanced the accumulation of dry matter, the uptake of N,P and K and the logding resistance, then reduced the population lodging percent, and finally significantly increased yield, quality and economic benefit.3. Based on the small seeder which was drived by samll four-wheel tractor as control, the sowing effect and cost-benefit in different compond seeders of minimum tillage and no-tillage which were integration of maize precision sowing and rotary-tiller with fertilizer spreader in lime concretion black soil region. The results showed that, compond seeder could significantly increased the regularity degree of sowing depth, emergence number, emergence rate and emergence uniformity, finally promoted grain yield, save cost and raising economic benefit. In addition, the quality of sowing and emergence, yield and economic benefit were higher when use rotation seeder of SGTNB—200Z4A8 from"Ya'ao in Xi'an", so it worth popularizing in large scale in lime concretion black soil region.
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