灌溉次数和施氮量对甜高粱生产性能及光合特性的影响

Effects of Irrigation Frequency and Fertilizer Application Rate on Production Performance and Photosynthetic Characteristics of Sweet Sorghum

为探讨宁夏引黄灌区甜高粱优质高效生产最佳灌溉次数和施氮肥量,试验采用双因素裂区试验设计,研究灌溉次数(W_(1):灌溉1次,W_(2):灌溉2次,W_(3):灌溉3次)和施氮梯度(F_(0):不施肥,F_(1):300 kg·hm^(-2),F 2:450 kg·hm^(-2),F_(3):600 kg·hm^(-2))对甜高粱生产性能、营养价值及光合特性的影响,并利用主成分分析方法(Principal component analysis,PCA)进行综合评价。结果表明:在灌溉次数相同条件下,随着施肥量的增加,甜高粱干草产量呈先增加后降低趋势,且在W_(1)F_(1)处理下达到最大值,为27110.54 kg·hm^(-2);W_(2)F_(1)处理的甜高粱粗蛋白含量最高,W_(1)F_(0)处理的相对饲喂价值最高,分别为7.32%和157.33;随着灌溉次数和施肥量的增加,灌溉水分利用效率、肥料偏生产力均呈先增加后降低趋势,且在W_(1)F_(1)处理时达到最大,分别为21.21 kg·m^(-3)和93.05 kg·kg^(-1)。PCA综合分析得出,灌溉1次(1050 m^(3)·hm^(-2))、施氮量为300 kg·hm^(-2)时,甜高粱综合表现最好,为最佳水肥调控组合,可在宁夏引黄灌区推广应用。

In order to explore optimal irrigation frequency and nitrogen application rate for the high-quality and high-efficiency production of sweet sorghum in Yellow River irrigation area of Ningxia,a two-factor split plot design was used to study the effects of irrigation frequencies(W_(1):irrigation once,W_(2):irrigation twice,W_(3):Irrigation three times)and nitrogen application gradients(F_(0):no fertilizer,F_(1):300 kg·hm^(-2),F 2:450 kg·hm^(-2),F_(3):600 kg·hm^(-2),)on the production performance,nutritional value and photosynthetic characteristics of sweet sorghum.Principal component analysis(PCA)was used for comprehensive evaluation.The results showed that under the same irrigation time,the hay yield of sweet sorghum increased first and then decreased with the increase of fertilizer rate,and reached the maximum of 27110.54 kg·hm^(-2)under W_(1)F_(1)treatment.The crude protein content of sweet sorghum in W_(2)F_(1)was the highest,and the relative feeding value in W_(1)F_(0)was the highest,7.32%and 157.33,respectively.With the increase of irrigation frequency and fertilizer application rate,irrigation water use efficiency and fertilizer partial productivity increased first,then decreased,and reached the maximum in W_(1)F_(1)treatment,21.21 kg·m^(-3)and 93.05 kg·kg^(-1),respectively.According to PCA comprehensive analysis,the comprehensive performance of sweet sorghum was the best when irrigation once(1050 m^(3)·hm^(-2))and nitrogen application rate was 300 kg·hm^(-2),which could be popularized and applied in Ningxia Yellow River irrigation area.