西北地区马铃薯施肥效应和经济效益分析

Yield response and economic benefit of fertilizer application on potato in Northwest China

2002-2011年在内蒙、甘肃、宁夏、青海4省进行田间试验研究马铃薯（ Solanum tuberosum L．）施用氮、磷、钾肥的增产效应和经济效益。试验设施氮（＋N）、不施氮（-N）、施磷（＋P）、不施磷（-P）、施钾（＋K）、不施钾（-K）处理。结果表明,施用氮、磷、钾肥平均增产分别为5657、3967、5341 kg/hm2,分别有95%、75%、81%的试验增产达显著水平（P〈0．05）,说明氮是影响马铃薯产量的主要因素,其次是钾,然后是磷。氮（ N）、磷（ P2 O5）、钾（ K2 O）肥的农学效率分别为37．6、45．0和44．9 kg/kg。施用氮、磷、钾肥平均分别增加收入5218、3683、4141元/hm2,平均产投比（ VCR）分别为9．3、12．7和8．8元/元。通过分析不同肥料价格和马铃薯价格下的VCR表明,随着施肥增产效应的增加,即使施肥量增加, VCR也增加。无论现在还是将来,西北地区马铃薯合理施用氮、磷或钾肥获得收益的概率超过75%,收益多少随增产效应、施肥量、肥料和马铃薯价格而变化。

Field trials were conducted in Northwest China during 2002 to 2011 to find yield response of potato （ Solanum tu-berosum L. ） to N, P or K fertilization and the economic returns. The treatments for each trial included a recommended rate of nutrient based on soil testing and a control treatment without specific nutrient, i. e. omission of N, P or K. Results indicated that yield response to N, P and K, on average, was 5 657, 3 967 and 5 341 kg/hm2 , and 95%, 75% and 81% of the trials showed significant （P〈0. 05） response, indicating that nitrogen was the first limiting factor followed by potassium and then phosphorus in potato production. The mean agronomic efficiency of N, P and K was 37. 6 kg/kg N, 45. 0 kg/kg P2 O5 and 44. 9 kg/kg K2 O, respectively. Economic analysis indicated that application of N, P and K fertilizer resulted in an average of 5 218, 3 683, and 4 141 yuan/hm2 income and the mean value cost ratio （VCR） of N, P and K was 9. 3, 12. 7and 8. 8, re-spectively. Estimation of VCR based on various prices of fertilizer and tuber indicated that VCRs for N, P and K fertilizer ap-plication increase with the increase of yield response even though fertilizer rate increases. At present or in the future appropriate application of N, P or K fertilizer on potato in Northwest China region can be profitable in more than 75% scenarios and how much income will be obtained depends on yield response, fertilizer rate, price of fertilizer and potato tuber.