半干旱区沟垄集雨种植谷子的肥料效应及其增产贡献

摘要

A field experiment was conducted under ridge-furrow rainfall harvesting planting model in 2013 (flood years) and 2014 (drought years) to explore the combined effect of planting model and fertilizer level on yield and fertilizer utilization efficiency of foxtail millet. A two-factor randomized block designed pot with two planting models (rainfall harvesting planting model, R; tradi-tional flat planting model, T) and four fertilizer levels (N 270 kg ha–1+P2O5 180 kg ha–1, H; N 180 kg ha–1+P2O5120 kg ha–1, M; N 90 kg ha–1+P2O5 60 kg ha–1, L; with no fertilizer as control) was used in the experiment. Plant height, leaf area, photosynthetic rate, water and fertilizer use efficiency, and source of yield increase of foxtail millet were analysed. Compared with T, R effectively promoted the photosynthetic physiology and growth of side row of foxtail millet, increasing plant height by 7.1%–23.5%, the top three leaves area by 1.7%–22.7%, Pn (photosynthetic rate) by 10.4%–20.3%, Tr (transpiration rate) by 8.0%–55.9%, and dry mat-ter by 9.8%–30.0% in different fertilization treatments. There was no significantly difference between the middle rows of R and T on the five indexes. R significantly improved water and fertilizer use efficiency. Application of nitrogen and phosphorus fertilizer significantly improved WUE, in flood years H was significantly higher than M and L, in drought years M was significantly higher than H and no significantly difference with L, Fertilizer use efficiency decreased with the increase of fertilization amount, which was significantly higher in L than in M and H in flood years, with significant difference between the treatments of fertilization in drought years. Effect of fertilizer was bigger than that of planting factor in contribution rate to foxtail millet yield. Contribution rate of fertilization increased by 27.8%–49.3% with increasing fertilizer amount in flood years, with significant, difference among treatments while these was no significant difference in all treatments in the drought years (19.2%–23.7%), Contribution rate of planting model was not significantly different between treatments in two years. Therefore, RH in flood years and RM in drought years could be regarded as a better farming management with high yield and high efficiency in semi-arid area of southern Ningxia.%研究沟垄集雨种植施肥水平对谷子生长的影响及其对产量的贡献, 为完善集雨种植技术理论体系及半干旱区谷子的合理施肥提供科学依据.在宁南旱农区进行了2个年型的二因素大田试验, 研究了沟垄半覆膜集雨(R)和传统裸地平作(T) 2种种植模式下4个施肥水平(高量N 270 kg hm–2+ P2O5180 kg hm–2, H; 中量N 180 kg hm–2+ P2O5120 kg hm–2, M; 低量N 90 kg hm–2+ P2O560 kg hm–2, L; 不施肥对照, CK)对谷子株高、叶面积、光合指标、干物质积累量和水肥利用效率的影响, 并分析了集雨模式下的增产贡献来源.结果表明: (1)集雨模式有效促进了边行谷子光合生理和生长, 在各施肥水平下谷子株高、顶三叶叶面积、Pn(净光合速率)、Tr(蒸腾速率)和生物量较平作模式分别提高7.1%～23.5%、1.7%～22.7%、10.4%～20.3%、8.0%～55.9%和 9.8%～30.0%; 中行各指标较平作模式均下降不显著.(2)集雨种植模式显著提高了谷子的水肥利用效率, 配施氮磷肥水分利用效率显著增加, 在丰水年高肥处理显著高于中、低肥处理, 欠水年中肥处理最高且显著高于高肥处理, 与低肥处理差异不显著; 肥料利用效率随着施肥量的增加而下降, 在丰水年低肥处理的肥料利用率显著大于高肥和中肥处理, 欠水年各施肥水平间差异显著.(3)施肥对谷子的增产贡献大于种植模式.施肥对产量的贡献率在丰水年随施肥量的增加而增加, 高、中、低施肥处理间差异显著, 达27.8%～49.3%, 欠水年各施肥处理间差异不显著(19.2%～23.7%); 种植模式贡献率在 2 年中各施肥处理间差异均不显著.综合考虑, 集雨模式在丰水年施高肥、欠水年施中肥可实现谷子高产高效生产.