内蒙古阴山北麓地区膜下滴灌马铃薯水肥高效利用生理机制

The northern region of Yinshan Mountains is the main production area of potato under dry farming, but lack of water resources. Therefore building the comprehensive technological system of water-saving, fertilizer-saving, high-yielding and high efficiency, and improving water and fertilizer use efficiency has been a very urgent issue. The objective of this experiment is to improve water and fertilizer use efficiency and achieve high yield and quality. Using the potato with drip irrigation under mulch film as the experimental materials, the major research content is as follows: study on the effects of irrigation and nitrogen fertilizer on the characters of time-space variation of water and nutrient in soil, and its relationship of yield components and quality formation, while make clear the influence of different irrigation amount, different nitrogen application methods and levels on yield formation and water and nutrient use, and the irrigation regime and optimal fertilizer model will be presented. The difference in nitrate-nitrogen leaching from soils under the growth period of potato and which raises the compensation uptake ability of nitrate in deep subsoil will be also studied, furthermore, to reveal the physiological ecology mechanism of high-efficient use of water and fertilizer in potato, and provide theoretical basis for building the comprehensive technological system of water-saving, fertilizer-saving, high-yielding and high efficiency. Such technical system can solve the problem of shortage of water resources and nutrient in northern region of Yinshan Mountains, and has important realistic meanings to improve water and fertilizer use efficiency, reduce production cost, increase production benefit, reduce environmental pollution and protect ecological environment.

本项目针对内蒙古阴山北麓旱作区马铃薯生产中水资源匮乏的实际问题，以膜下滴灌马铃薯为研究对象，以提高水、肥（氮）利用效率为中心，以高产、高效为目标，在不同灌水、施肥条件下，研究灌水、施氮对土壤水分、养分时空变化特征的影响及其与马铃薯产量构成因素、块茎营养品质形成的关系，阐明不同灌水量、不同施氮方式、施氮量对产量形成和水肥利用的制约表现，明确实现膜下滴灌马铃薯节水、省肥、高产、高效的合理灌水制度和施肥制度；通过水肥控制及大田实证研究，明确马铃薯根系带土壤硝态氮淋洗的差异及对土壤深层硝态氮的补偿吸收能力，深入揭示马铃薯水肥高效利用的生理生态机制，为建立马铃薯节水、省肥、高产、高效栽培技术体系提供理论依据。该技术体系的建立，对阴山北麓旱作农区缓解有限水肥资源的供需矛盾，提高其利用效率，降低生产成本，提高种植效益，减少环境污染、保护生态环境等都具有重要的现实意义。

本项目研究了阴山北麓地区膜下滴灌马铃薯不同灌水量、灌水次数、灌水时期、施氮量及水氮耦合等因素对马铃薯植株生长、光合特性、抗逆生理指标、产量及品质、不同土层硝态氮、水分含量的时空变化及分布特征的影响。主要研究结果如下：.（1）总灌水量、灌水时期、灌水次数不同，均会导致膜下滴灌马铃薯不同土层土壤硝态氮含量、水分含量的时空变化不同，进而对马铃薯植株生长产生不同影响。随灌水量增加，土壤水分下渗量增大，土壤硝态氮下移量增多，0-20cm土层硝态氮下降，20-40cm、40-60cm土层含量提高。单次灌水量超过300m3/hm2时，60-80m、80-100cm土层硝态氮含量也会明显增加，特别是施氮肥后及时灌水更为明显。总灌水量相同情况下，减少灌水次数，增大单次灌水量，会降低灌水利用率，增大硝态氮流失。.（2）马铃薯全生育期内，0～40 cm土层属于土壤水分的“急变层”，变化波动较大；40～60 cm土层属于“活跃层”，受根系生长影响较大；而80～120 cm土层属于“相对稳定层”，该层水分不易渗透，一般保持较高含水率，但在块茎膨大期也会出现小幅下降。.（3）不同土层土壤硝态氮含量与灌水量、追氮量的相关性受追氮量、灌水量影响明显。0-20cm土层硝态氮含量与灌水量呈极显著负相关、而与追氮量呈极显著正相关，20-40cm、40-60cm土层硝态氮含量与灌水量、追氮量均呈显著或极显著正相关，60cm以下土层硝态氮含量与灌水量、追氮量的正相关程度均逐渐降低。.（4）阴山北麓旱作区，膜下滴灌马铃薯总灌水量以不超过1725m3/hm2、单次灌水量不超过300m3/hm2、灌水次数6-8次为宜，少量多次的滴灌方式有利于马铃薯块茎均匀膨大生长，对提高商品薯率有利。适宜灌溉制度：苗期、块茎形成初期、块茎形成末期、块茎增长初期、块茎增长中期、块茎增长末期、淀粉积累初期分别滴灌水量150、300、225、300、300、225、225m3/hm2 。配套施肥制度为：在底施N 75.0 kg/hm2，P2O5 150.0 kg/hm2，K2O 210.0 kg/hm2的基础上，于块茎形成期至增长期按4：6合计追施氮素180kg/hm2。