不同施肥对黑河中游边缘绿洲沙地农田玉米产量及土壤硝态氮积累影响的初步研究

Effects of Fertilization on Grain Yield and Nitrate Accumulation in Oasis Sandy Farmland in Middle Heihe River Basin

在黑河中游边缘绿洲的沙地农田进行不同施肥对玉米产量及土壤硝态氮积累的试验研究表明,有机肥与化肥配合施用增加作物产量。不同肥料处理,玉米籽粒产量由高到低的顺序依次为NPK3M1(高量氮磷钾肥低量有机肥配施:N-P2O5-K2O-M,300-225-225-15000kg.hm-2)>NPK2M2(中量氮磷钾肥中量有机肥配施:N-P2O5-K2O-M,225-135-135-22500kg.hm-2)>NPK3(高量氮磷钾肥配施:N-P2O5-K2O-M,300-225-225-0kg.hm-2)>NP1M3(低量氮磷肥高量有机肥配施:N-P2O5-K2O-M,150-90-0-30000kg.hm-2)>NP3(高量氮磷肥配施:N-P2O5-K2O-M,300-225-0-0kg.hm-2)>NPK1M3(低量氮磷钾肥高量有机肥配施:N-P2O5-K2O-M,150-90-90-30000kg.hm-2)>NPK2(中量氮磷钾肥配施:N-P2O5-K2O-M,225-135-135-0kg.hm-2)>NPK1(低量氮磷钾肥配施:N-P2O5-K2O-M,150-90-90-0kg.hm-2)>M3(单施有机肥:N-P2O5-K2O-M,0-0-0-30000kg.hm-2)。高量氮磷钾肥配合低量有机肥处理玉米产量最高,单施有机肥处理产量最低。与只施有机肥处理相比,各处理产量分别增加37.68%、33.43%、28.32%、25.10%、24.60%、23.84%、21.46%、11.30%。在不施有机肥的3个氮磷钾施肥处理中,玉米产量和氮肥农学利用效率(AE)随施肥量的增加而增加,但当施肥量超过225-135-135kg.hm-2(N-P2O5-K2O)时,玉米产量和AE不再随施肥量的增加而增加。与不施有机肥处理不同,在氮磷钾配施有机肥的3个处理中,AE随化肥施用量的增加而减少,有机肥的施用使得化肥利用效率增加。不同施肥处理对土壤硝态氮的积累与分布有显著的影响,土壤硝态氮受土壤质地影响主要分布于0～40cm土壤层次内,与化肥单施相比,有机肥导致土壤中硝态氮的积累。因此,从持续农业发展及保护生态环境等方面考虑,有机无机肥配合施用是增加绿洲农田土壤生产力,维持和提高土壤质量的有效途径,与当地农户普遍采用的施肥量相比,有机无机配施的情况下,适度减少化肥投入33%是合理的施肥对策。

A field experiment was conducted on sandy farmland to determine the effects of different fertilization on maize yield,agronomic nitrogen use efficiency（AE）,content,and accumulation of nitrate-N in soil profiles of 0~300 cm.Twenty-seven plots in which include nine treatments and 3 replicates were designed.The maize was harvested for grain yield and straw yield in 2007.After maize harvest,the soil was sampled from the 0~300 cm depths to determine NO-3-N content.The maize yield decreased in the order of NPK3M1（N-P2O5-K2O-M,300-225-225-15 000 kg·hm-2）NPK2M2（N-P2O5-K2O-M,225-135-135-22 500 kg·hm-2）NPK3（N-P2O5-K2O-M,300-225-225-0 kg·hm-2）NP1M3（N-P2O5-K2O-M,150-90-0-30 000 kg·hm-2）NP3（N-P2O5-K2O-M,300-225-0-0 kg·hm-2）NPK1M3（N-P2O5-K2O-M,150-90-90-30 000 kg·hm-2）NPK2（N-P2O5-K2O-M,225-135-135-0 kg·hm-2）NPK1（N-P2O5-K2O-M,150-90-90-0 kg·hm-2）M3（N-P2O5-K2O-M,0-0-0-30 000 kg·hm-2）[N-nitrogen,P-phosphorus,K-potassium,M-farmyard manure application].Compared with only treatment M,maize yield was 3768%,3343%,2832%,2510%,2460%,2384%,2146%,1130% higher respectively.Among three treatments of N-P-K without M,maize yield and AE increased with increase of fertilizer rate,and ceased until 225-135-135 kg hm-2（N-P2O5-K2O）were supplied.On the contrary,AE decreased with increase of fertilizer rate in treatments of N-P-K with M;accumulation and distribution of NO-3-N in soil was significantly affected by application of manure fertilizer.Soil layer between 0~40 cm is the main layer of NO-3-N distribution affected by soil texture.Application of manure,especially combination of chemical fertilizer with manure increased soil NO-3-N content as compared to chemical fertilizer alone.These suggest that it is important to balance the application of chemical fertilizer and manure so as to protect soil and underground water from potential NO-3-N pollution and keep high productivity in oasis agro-ecosystem.