【作者】 沈学善；

【导师】 李金才；

【作者基本信息】 安徽农业大学 ， 作物栽培学与耕作学， 2010， 博士

【摘要】 作物秸秆含有大量有机质和植物生长所必需的氮、磷、钾及其它中微量元素。秸秆还田可以改土培肥、蓄水保墒、促进作物生长,提高籽粒产量。秸秆还田是现代农业发展的必然趋势。安徽淮北小麦、玉米一年两熟农作区,土壤主要为砂姜黑土,质地粘重,易旱易涝,适耕期短,且有机肥投入不足,农业机械不发达,农机农艺不配套,麦秸还田影响下茬玉米的播种出苗,导致麦秸直接还田率较低。针对生产中存在的问题,本文在砂姜黑土区小麦玉米轮作模式下,通过两年大田试验,系统研究小麦玉米秸秆两季还田配施化肥对夏玉米的生理生态效应,探讨小麦秸秆适宜的还田方式,筛选能在砂姜黑土区小麦秸秆还田条件下满足玉米精量播种要求的播种机械,为实现小麦秸秆机械化直接还田,玉米精量播种施肥镇压一体化高效栽培提供理论依据和实践尝试。主要研究内容和结果如下:1.以紧凑型玉米品种郑单958为材料,研究小麦秸秆全量粉碎覆盖还田和玉米秸秆全量粉碎翻埋还田与化肥配施对夏玉米的生理生态效应。结果表明,在小麦秸秆全量粉碎灭茬后,用东方红X850型75马力拖拉机驱动西安亚澳SGTNB—200Z4A8型旋耕施肥播种机直接播种玉米的条件下,小麦玉米秸秆两季还田处理玉米的播种质量与对照差异不显著,而其出苗数和出苗率显著高于对照。经间、定苗后,可形成苗全、苗匀、苗壮的高产玉米群体。小麦玉米秸秆两季还田而不施化肥处理玉米幼苗的株高、干重、叶面积和根系活力均显著低于对照,其吐丝后的群体叶面积指数和叶片净光合速率也显著低于对照,造成其群体干物质积累降低,对氮磷钾元素的吸收减少,植株抗倒性能下降,群体倒折率增多,最终产量和经济效益显著低于对照。而小麦玉米秸秆还田配施化肥处理玉米幼苗的株高、干重、叶面积和根系活性显著高于对照,其吐丝后的叶面积指数和叶片净光合速率也显著高于对照,从而增加其群体干物质积累量和氮磷钾元素的吸收量,提高植株抗倒性能,降低群体倒折率,最终显著提高籽粒产量,改善籽粒品质,提高经济效益。且小麦玉米秸秆两季还田配施化肥处理籽粒产量显著高于秸秆单季还田配施化肥处理。2.以小麦机械收获后秸秆直接覆盖还田为对照,研究麦秸粉碎抛撒还田(在小麦收割机上加装秸秆粉碎抛撒装置)和麦秸灭茬覆盖还田(小麦机械收获后采用灭茬机灭茬)对夏玉米的生理生态效应。结果表明,在用东方红X850型75马力拖拉机驱动西安亚澳SGTNB—200Z4A8型旋耕施肥播种机播种玉米的条件下,不同麦秸处理方式间玉米的播种质量差异不显著,而麦秸灭茬覆盖和粉碎抛撒处理玉米的出苗数和出苗率显著高于麦秸直接覆盖处理。各处理经间、定苗后,可形成苗全、苗匀、苗壮的高产玉米群体。麦秸灭茬覆盖和粉碎抛撒覆盖处理玉米幼苗的株高、干重、叶面积和根系活力均显著高于对照,其吐丝后的群体叶面积指数和叶片净光合速率也显著高于对照,造成其群体干物质积累量增多,对氮磷钾元素的吸收增强,植株抗倒性能提高,群体倒折率下降,最终显著提高籽粒产量,改善籽粒品质,增加经济效益。3.以小四轮带动的小型播种机为对照,研究不同旋耕播种施肥镇压一体化复式少免耕播种机在砂姜黑土区的玉米播种效果和成本效益。结果表明,复式播种机可显著提高播深整齐度、出苗数和出苗率及出苗均匀度,最终提高籽粒产量,节约成本,增加经济效益,且以西安亚奥SGTNB—200Z4A8型播种机播种、出苗质量、产量和经济效益较高,值得在砂姜黑土区大面积推广使用。更多还原

【Abstract】 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.更多还原