灌水频率和施肥量对滴灌马铃薯生长、产量和养分吸收的影响

【目的】针对陕北榆林风沙土马铃薯灌水施肥不合理及水肥利用效率低的问题,通过研究滴灌施肥条件下不同的灌水频率和施肥量对马铃薯生长、产量及养分吸收利用的影响,以期科学地对马铃薯进行水肥调控,为实际生产提供参考依据。【方法】试验于2016年5—10月在陕西省榆林市农业科技示范园区内进行,试验设置了3个灌水频率D1 (4 d)、D2 (8 d)、D3 (10 d)和3个施肥量(N、P_2O_5、K_2O)水平,即F1 (100、40、150kg/hm^2)、F2 (150、60、225 kg/hm^2)、F3 (200、80、300 kg/hm^2)组合,共9个处理。在生育期对马铃薯生长指标进行观测,收获时统计产量及产量构成因素。【结果】1)同一灌水频率下,F3处理的株高、茎粗、叶面积和产量显著高于F1和F2处理,肥料偏生产力在F1处理下最高,而水分利用效率受施肥量的影响不显著,养分利用效率随着施肥量的增加而减小。F3处理的产量达41518 kg/hm^2,比F1和F2处理分别提高11.75%和8.52%,F1处理下肥料偏生产力为128.12 kg/kg,比F2和F3处理的高出45.67%和78.99%。2)在同一施肥量下,马铃薯的生长指标、产量和肥料偏生产力均在D2处理达到最大值,D2处理下的产量和肥料偏生产力分别为42932kg/hm^2和105.88 kg/kg,而D1处理下水肥利用效率最高,但D1和D2之间水分利用效率差异不显著。从水肥交互作用来看,D2F3的产量和水分利用效率最高,分别为44870 kg/hm^2,107.39 kg/(mm·hm^2),D2F1的肥料偏生产力最高,为142.02 kg/kg。【结论】合理的灌水频率与施肥量不仅能维持马铃薯较好的生长特性,而且能获得较大的经济效益。综合产量与节水节肥因素,D2F3处理(8 d,N 200 kg/hm^2、P_2O_5 80 kg/hm^2、K_2O 300kg/hm^2)可作为基于本试验条件下较适宜的灌水施肥组合。

Effects of irrigation frequency and fertilizer rate on growth,tuber yield and nutrient uptake of drip-irrigated potato

【Objectives】 In view of inappropriate irrigation and fertilization as well as low water and fertilizer use efficiency in potato planted in sand soil in Yulin area of northern Shaanxi province, field experiment was conducted to examine the effects of irrigation frequency and fertilizer rate on growth, yield and nutrient use efficiency of potato (Solanum tuberosum L.) under fertigation in order to scientifically regulate water and fertilizer use and provide scientific reference for potato production. 【Methods】 Field experiment was carried out in Agricultural Science and Technology Demonstration Areas of Yulin city, Shaanxi province from May to October in 2016. There were total of 9 treatments combining three irrigation frequency levels, i.e. D1 (4 d), D2 (8 d) and D3 (10 d), and three fertilization levels based on different ratios of N, P₂O₅, K₂O, i.e. F1 (100, 40, 150 kg/hm2), F2 (150, 60, 225 kg/hm2) and F3 (200, 80, 300 kg/hm2). Growth indices were measured during the growing season, tuber yield and its components were measured at harvest. 【Results】 At the same irrigation frequency, there was a positive correlation between growing indices and the fertilizer rates, and the tuber yield increased with increase of fertilizer rates, but the partial fertilizer productivity (PFP) and the nutrient use efficiency decreased. There was no significant correlation between water use efficiency (WUE) and fertilizer rate, and the average tuber yield of F3 was 41518 kg/hm2, 11.75% and 8.52% higher than F1 and F2. The PFP of F1 was 128.12 kg/kg, 45.67% and 78.99% higher than F2 and F3. At the same fertilizer rate, there was a quadratic correlation between yield, PFP and irrigation frequency. D2 had the greatest tuber yield of 42932 kg/hm2 and highest PFP of 105.88 kg/kg, and D1 resulted in the highest WUE and nutrient use efficiency, but had no difference with D2. As for interaction between irrigation frequency and fertilizer rate, the highest tuber yield and WUE were attributed to D2F3 with 44870 kg/hm2 tuber yield and 107.39 kg/(mm·hm2), respectively. D2F1 had the highest PFP of 142.02 kg/kg. 【Conclusions】 Reasonable irrigation frequency and fertilizer rate not only sustained good growth characteristics of potato, but also resulted in the maximum economic benefit. In comprehensive consideration of yield, water and fertilizer saving, the treatment of D2F3(8 d, N 200 kg/hm2, P₂O₅ 80 kg/hm2, K₂O 300 kg/hm2)was appropriate water and fertilizer combination under the experimental conditions.