荒漠区灰钙土土壤养分对甘草经济效益的影响

[目的]研究甘肃省河西走廊荒漠区灰钙土甘草氮磷钾锌最佳施肥量,为甘草产业可持续发展提供技术支撑。[方法]在甘肃省张掖市民乐县三堡镇的灰钙土上,采用田间试验方法,进行了甘草氮磷钾锌最佳经济效益施肥量的研究。[结果]甘草鲜根产量随氮磷钾锌施肥量梯度的增加而增加,但每1 kg氮磷钾锌增产量则随氮磷钾锌施肥量梯度的增加而递减;随着氮磷钾锌施肥量梯度的增加,甘草边际产量和边际产值在下降,边际利润最终出现负值;甘肃省河西走廊荒漠区灰钙土甘草氮磷钾锌经济效益最佳施肥量分别为0.46,0.26,0.16和0.02 t/hm~2,最佳施肥量时的理论鲜根产量分别为12.81,13.35,13.06,12.76 t/hm~2。[结论]在氮磷钾含量较低,有效锌缺乏的灰钙土上,甘草施用氮磷钾锌具有明显的增产效果,但最高产量的施肥量并不是最佳经济效益施肥量,最佳经济效益施肥量必然低于最高产量施肥量。

Effects of Soil Nutrients of Sierozem in Desert Area on Economic Benefits of Liquorice

[Objective] The economic benefits of optimum fertilization of nitrogen, phosphorus, potassium and zinc of licorice in sierozem of the desert region area of Gansu Corridor were studied in order to provide technical support for the sustainable development of licorice industry.[Methods] A field experiment was carried out to study the economic benefits of optimum fertilization of nitrogen, phosphorus, potassium and zinc in sierozem of Sanbao Town, Minle County, Zhangye City, Gansu Province.[Results] With the increase of the fertilization of nitrogen, phosphorus, potassium and zinc, the fresh root yield of licorice was increased, but the increased amount of licorice under per 1 kg fertilization was decreased. The marginal yield and value of licorice were decreased, and the marginal profit showed a negative value eventually. In the desert region area of Gansu Corridor, the optimum application rate of nitrogen, phosphorus, potassium and zinc was 0.46, 0.26, 0.16 and 0.02 t/hm², and the theoretical yield of fresh root at the optimum application rates were 12.81, 13.35, 13.06, 12.76 t/hm².[Conclusion] Sierozem has the low content of nitrogen, phosphorus, potassium and zinc, the application of nitrogen, phosphorus, potassium and zinc to licorice can increase the yield obviously, however, the fertilizer amount with the highest yield is not the optimum fertilization of economic benefits. The best fertilization amount is necessarily lower than that.