陕北马铃薯对膜下滴灌施肥供水供肥的响应研究

China is boosting potato acreage to transform the crop into the country's fourth staple food after rice, wheat and maize, said Yu Xinrong, vice minister of agriculture, at a seminar on January 6, 2015. The Northern Shaanxi is one of five big potato advantage areas in our country. But it is dry and little rain. However, there is still exists the traditional idea of field management that the best technology is fertilizer high and water frequently. Then the problem is the low water and fertilizer use efficiency and high fertilizer input. Field experiments were conducted to study the effects of drip irrigation regimes on potato (Solanum tuberosum L.) growth, tuber yield and quality, and water and fertilizer use efficiency when grown under plastic mulch in Northern Shaanxi in 2017, 2018, 2019 and 2020. The combination of field experiments and theoretical analysis method were used in this study. The objectives of this study were to (1) illuminate the effects of different drip fertigation regimes under continuous plastic mulch on potato growth, tuber yield, water use efficiency and tuber quality; (2) reveal the impacts of different drip fertigation regimes under continuous plastic mulch on potato root zone water and fertilizer dynamic distribution and migration mechanism; (3) explore the influence of different drip fertigation regimes under continuous plastic mulch on the fertilizer absorption, transport, distribution and use efficiency and (4) set up a forecasting model which is based on drip discharge, irrigation and fertilizer rate, and the suitable for potato is located in Northern Shaanxi. The results may provide the theoretical and experimental basis for field management and increasing yield and efficiency affects for popularization and application of potato in Northern Shaanxi.

2015年1月6日，农业部副部长余欣荣表示，我国将启动马铃薯主粮化战略，陕北地区是我国五大马铃薯优势种植区之一，但该地区水资源紧缺问题严重，加之仍旧存在“肥大水勤”的传统观念，致使过量施肥和水肥利用效率偏低。本项目以陕北马铃薯为研究对象，利用滴灌施肥供水供肥技术，采用田间试验和理论分析相结合的方法，研究膜下滴灌施肥供水供肥对陕北马铃薯生长、产量和品质的影响；阐明膜下滴灌施肥供水供肥对陕北马铃薯根区水分养分动态分布规律和迁移机理；探索陕北马铃薯对膜下滴灌施肥供水供肥模式下，水分养分吸收、转运、分配和利用规律；提出适用于陕北马铃薯的较优滴灌施肥策略，建立基于滴头流量、灌水量和施肥量的田间产量预测模型。为作物水分养分耦合高效利用技术提供科学依据，实现陕北马铃薯的增产增效和滴灌施肥技术的推广应用。

本项目从以往研究灌水量和施肥量对马铃薯形态生理影响的基础上，进一步研究不同生育阶段亏缺灌溉与各阶段不同肥料配比对作物生长、产量和品质的耦合效应；由单纯研究灌水水平和施肥水平对作物需水需肥的调节过程，深入到各生育阶段亏缺灌溉和不同肥料配比对根区土壤水分养分的有效性研究。力求探明黄土塬区主要粮食作物各生育阶段的水肥精准调控策略及作用机理，进一步揭示灌溉施肥条件下作物各生育阶段对水肥的响应规律，寻求作物产量、品质和水肥利用效率的联合提高途径，提出切实可行的田间水肥精准管理技术，在陕北地区推广应用，为陕北地区农业增产增效发力。.确定了土壤硝态氮与土壤水分动态迁移交互影响因素，建立了较优水肥管理目标的高效选择机制，构建了作物水分-养分-产量-品质综合生产函数定量关系，提出了作物品质最优下的水肥供应技术。高水中施肥下马铃薯有较高的产量和氮肥利用率以及较低的土壤硝态氮含量，低水中肥有最大的维生素C、可溶性糖和番茄红素含量以及较高的水分利用效率。灌水量对番茄水分利用效率的影响极显著，作物耗水量与灌水量正相关，与施肥量无显著性关系。马铃薯可溶性蛋白和维生素C 对施肥比灌溉更敏感，含糖量随着施肥量的增加而降低，马铃薯块茎产量与含糖量呈负相关。在引入TOPSIS 模型，以及采用PCA 分析情况下，提出了灌水周期为8 天，灌水水平为80%ETc，施肥量为N−P2O5−K2O 为200−150−300 kg ha-1，是砂土土质马铃薯种植的最佳水肥组合。