江苏地区是我国重要的稻麦轮作种植区，保障该地区小麦产量对确保国家的粮食安全有着重要意义。作为小麦生长必须的营养元素，氮素的投入是小麦增产的关键。由于气候条件以及土壤因子的影响，苏南地区的小麦种植以及肥料施用多以撒播撒施为主，氮肥损失严重，利用率低，小麦产量不高，对生态环境造成负面影响。因此，如何提高小麦氮肥利用率，减少麦田氮素损失是该地区亟需解决的问题。随着肥料工艺的发展以及农机技术的进步，为创新太湖地区小麦播种施肥方式，提高小麦产量与氮素利用率，降低环境风险提供了可能。本研究以南京市江宁区汤山街道阜庄社区长期水旱轮作试验田为研究对象，开展小麦不同播种施肥方式和肥料类型的田间试验，比较研究撒播撒施（M）、条播正深施（D）以及条播侧深施（SD）三种播种施肥方式下，分别施用普通化肥（CF）和缓释尿素（CRU）对小麦生长的影响及其环境效应。研究结果表明：
1.不同的播种施肥方式显著影响小麦的生长情况，正位深施下普通肥料处理与缓控释肥处理皆能促进小麦的生长，提高有效穗数和千粒重，促进地上部的干物质积累，实现小麦增产。D-CF处理比M-CF和SD-CF处理分别增产了32.89%和1.48%，D-CRU比M-CRU和SD-CRU分别增产了44.81%与6.08%，而D-CRU处理比D-CF产量增加了13.31%。不利年份倒伏田块的实际样本分析发现，D-CF处理的倒伏率显著高于M-CF和D-CRU处理田块，D-CF田块株高和穗重与茎鞘叶重比最高，基部节间维管束面积和数量、三素（纤维素、半纤维素与木质素）含量均低于其他处理。综合分析结果说明，缓控释肥深施（D-CRU处理）可以优化小麦根系构型，增加小麦茎秆强度，降低小麦倒伏发生风险。
2.麦田耕层土壤无机氮含量在不同处理下表现各不相同，普通肥料处理下耕层土壤无机氮含量随小麦生育期的推进而逐渐降低，而缓控释肥处理整体比较平稳，后期有所增加，更符合小麦的生长需求。肥料的精准布施可以减少氮素迁移的距离，增加根系周围土层的无机氮含量，从而提高肥料利用率。本研究发现缓控释肥处理的氮素利用率高于普通肥料处理，肥料深施处理则高于肥料撒施处理，正位深施处理优于侧位深施处理，其中D-CRU处理下氮素表观利用率最高（43.32%），而M-CF处理最低，仅为25.79%。
3.缓控释肥的施用可以减少麦田氨挥发、N2O及径流氮排放。普通肥料分次追施是造成氨挥发排放增加的主要原因。肥料深施可以减少氨挥发及N2O排放，但仅在缓控释肥处理上效果显著。
4.D-CRU处理的经济效益最好，相较于D-CF提高了23.81%。D-CRU处理的增产率、净利润增加率、氮盈余减少率及氨挥发减排率均最高，分别为50.52%、551.92%、58.97%及87.60%，同时其N2O的减排率为47.50%仅次于SD-CRU处理的59.01%。整体看来缓控释肥正位深施是一个兼具经济效益以及环境效益的播种施肥方式。
综上，缓控释肥正位深施可以更好的满足小麦在生育后期氮素需求，增加氮素利用率，实现小麦增产并有效降低环境风险，是一种稳产减排的精简施肥技术。

Jiangsu is an important rice wheat rotation planting area in China. Ensuring wheat yield in this area is of great significance to ensure national food security. As a necessary nutrient element for wheat growth, nitrogen input is the key to increase wheat yield. Due to the influence of climate conditions and soil factors, wheat planting and fertilizer application in southern Jiangsu are mainly sowing and application, which not only increases the risk of fertilizer nitrogen loss, reduces the nitrogen utilization rate, affects the formation of wheat population and yield, but also causes a variety of ecological and environmental problems. Therefore, how to improve the nitrogen use efficiency of wheat and reduce the nitrogen loss in wheat field is an urgent problem to be solved in this area. With the development of fertilizer technology and the progress of agricultural machinery technology, it is possible to innovate the sowing and fertilization methods of wheat in Taihu Lake area, improve wheat yield and nitrogen utilization rate, and reduce environmental risks. This study intends to take the long-term flood and drought rotation experimental field in Fuzhuang community, Tangshan street, Jiangning District, Nanjing as the research object, carry out field experiments of different sowing and fertilization methods and fertilizer types of wheat, and compare and study the effects of common chemical fertilizer (CF) and slow and controlled release urea (CRU) on wheat growth and its environmental effects under three sowing and fertilization methods: manual spreading (M)、deep construction (D) andside-deep construction (SD). The results show that:
1. Different sowing and fertilization methods significantly affect the growth of wheat. Under positive and deep application, both ordinary fertilizer treatment and slow-release and controlled-release fertilizer treatment can promote the growth of wheat, improve the number of effective panicles and 1000 grain weight, promote the dry matter accumulation in the upper part of the ground, and increase the yield of wheat. Under d-cf treatment, compared with M-CF and SD-CF treatment, the yield increased by 32.89% and 1.48% respectively, D-CRU increased by 44.81% and 6.08% respectively, and D-CRU treatment increased by 13.31% compared with D-CF treatment.The actual sample analysis of lodging fields in adverse years found that the lodging rate of D-CF treatment was significantly higher than that of M-CF and D-CRU treatment. The plant height, spike weight and stem sheath leaf weight ratio of D-CF field were the highest, and the area and number of vascular bundles in basal internodes and the contents of three elements (cellulose, hemicellulose and lignin) were lower than those of other treatments. The comprehensive analysis results showed that deep application of slow and controlledrelease urea (D-CRU) could optimize wheat root architecture, increase wheat stem strength and reduce the risk of wheat lodging.
2. The content of soil inorganic nitrogen in the plough layer of wheat field is different under different treatments. Under the treatment of common fertilizer, the content of soil inorganic nitrogen in the plough layer gradually decreases, while under the treatment of slow-release and controlled-release fertilizer, it is relatively stable and increased in the later stage, which is more in line with the growth needs of wheat. At the same time, the precise application of fertilizer can reduce the distance of nitrogen migration and increase the content of inorganic nitrogen in the soil layer around the root system. This study found that the highest nitrogen absorption under D-CRU treatment was 43.32%,while M-CF treatment was the lowest, only 25.79%.
3. The application of slow and controlled release fertilizer can reduce the environmental emission of ammonia volatilization, N2O and runoff in wheat field. The repeated application of common fertilizer is the main reason for the increase of ammonia volatilization emission. Deep application of fertilizer can reduce ammonia volatilization and N2O emission, but only in slow and controlled-release fertilizer treatment.
4.The economic benefit of D-CRU treatment is the best, which is 23.81% higher than that of D-CF.D-CRU treatment has the highest yield increase rate, net profit increase rate, nitrogen surplus reduction rate and ammonia volatilization emission reduction rate, which are 50.52%, 551.92%, 58.97% and 87.60% respectively. At the same time, its N2O emission reduction rate is 47.50%, second only to 59.01% of SD-CRU treatmentOn the whole, positive deep application of slow and controlled-release fertilizer is a sowing and fertilization method with both economic and environmental benefits.
It can be inferred from the above that the positive and deep application of slow-release and controlled-release fertilizer can better meet the nitrogen demand of wheat in the later growth stage, promote the growth and development of wheat, increase the nitrogen utilization rate, increase the yield of wheat and reduce the environmental risk. It is a simplified fertilization technology for stable yield and emission reduction.