西北干旱区甜高粱种植水肥配比模式研究

Optimal Fertigation and Irrigation for Sweet Sorghum Production in Arid Regions in Northwest China

【目的】研究适合西北干旱区甜高粱种植的高产、节水省肥和高经济效益的水肥配比模式。【方法】以河西走廊边缘荒漠绿洲区为研究区,通过农田小区随机区组试验,设置3个灌溉定额梯度6 000 m^(3)/hm^(2)(W1)、7 200 m^(3)/hm^(2)(W2)、8 400 m^(3)/hm^(2)(W3)和3个施肥梯度450 kg/hm^(2)(F1)、600 kg/hm^(2)(F2)、750 kg/hm^(2)(F3)的水肥互交处理方式,共计9种水肥组合,分析不同水肥配比模式对甜高粱生长发育、生物产量、水肥利用效率和经济效益的影响。【结果】(1)灌溉量对甜高粱株高、茎粗和生物产量的影响不显著,但施肥量对上述指标影响显著,且水肥交互作用对株高和生物产量影响显著;(2)W1F3处理下的株高333.1 cm、茎粗22.63 mm、生物产量29.35 t/hm^(2)和灌溉水生产力3.80 kg/m^(3)均最大,分别比最大灌溉施肥量处理组合(W3F3)提高12.16%、11.29%、30.82%和87.19%,且甜高粱产量收益26 418.84元/hm^(2)、纯收益15 850.73元/hm^(2)和产投比2.50%分别比W3F3处理组合提高30.84%、88.17%和45.35%;(3)株高、茎粗、节间数、叶片数、叶片干质量、茎秆干质量、穗干质量和茎秆汁液糖锤度均与生物产量正相关。除甜高粱出汁率外,其他指标对生物产量产生正向直接效应,其中茎粗、株高、叶片数和茎秆干质量对生物产量的正向直接效应高于其他指标。【结论】灌溉量为6 000 m^(3)/hm^(2),施肥量为750 kg/hm^(2),可作为西北干旱区甜高粱种植科学的水肥配比模式。

【Background】Sweet sorghum has emerged as a crop with multiple usage ranging from feeding animals to being used for biofuel to sugar production.The large diurnal temperature variation in arid areas in northwest China is suitable for sweet sorghum growth,and its marginal lands including saline-alkali lands and sandy lands have become a main sweet sorghum production base in China.However,there is a lack of understanding about its optimal fertilization and irrigation.【Objective】This paper is to fill this gap by experimentally studying how irrigation and fertilization combine to affect growth and yield of sweet sorghum in these regions.【Method】The experiment was conducted in a desert oasis on the edge of Hexi corridor.It compared three irrigation amounts:6000 m3/hm2(W1),7200 m3/hm2(W2)and 8400 m3/hm2(W3),and three nitrogen fertilizations(N-P2O5-K2O with mass fractions of N,P and K all being 15%):450 kg/hm2(F1),600 kg/hm2(F2)and 750 kg/hm2(F3).Overall,there were nine treatments which were arranged randomly in the field.In each treatment,we measured the growth traits and ultimate yield of the sorghum.【Result】①The irrigation amount did not show significant effects on plant height,stem thickness and biological yield,but the fertilization did,with irrigation and fertilization combining to affect plant height and biological yield at significant level.②W1F3 was optimal in terms of increasing plant height(to 333.1cm),stem thickness(to 22,63 cm),biological yield(to 29.35 t/hm2)and water productivity(to 3.80 kg/m3),where were 12.16%,11.29%,30.82%and 87.19%up,respectively,compared to those in W3F3;its associated yield income,net income and production-to-investment ratio was 26418.84 Yuan/hm2,15850.73 Yuan/hm2 and 2.50%respectively,increasing by 30.84%,88.17%and 45.35%,compared with that in W3F3.③Plant height,stem thickness,the number of internodes and leaves,leaf dry mass,stem dry quality,ear dry quality and stalk juice sugar hammer were all positively correlated with biological yield.In addition to juice yield,other traits including the stem thickness,plant height,leaf number and stem quality,were also found to positively affect biological yield.【Conclusion】Irrigation of 6000 m3/hm2 coupled with 750 kg/hm2 of nitrogen fertilization is optimal for growth and ultimate yield of the sweet sorghum in northwestern China.