供氮水平和有机无机配施对片麻岩土壤谷子生长及土壤硝态氮的影响

在片麻岩新成山地土壤上,设置0,120和300 kg/hm2 3个施氮量,以不施氮肥(CK)为对照,在每个施氮水平下设置了50％有机肥50％尿素(用Y表示)和100％尿素(用N表示)2个副处理,研究了不同氮素水平下有机无机肥料配施对谷子生长及土壤硝态氮的影响.结果表明:在该试验条件下,与不施氮肥处理(CK)相比,各施氮处理的谷子产量均显著增加,当施氮量达到120 kg/hm2时产量达到最高,之后施氮量提高到300 kg/hm2谷子产量并没有显著增加；从0～60 cm土壤剖面中硝态氮分布的差异可以看出:在相同施肥方式下,土壤的硝态氮含量随施氮量的增加而增加,以0～40 cm土层变化最明显,有机肥与尿素配合施用,可以协调土壤氮素的供应,显著降低土壤NO3--N的含量.

Effect of nitrogen application rate and its combination with organic manure on millet growth and nitrate distribution in gneiss soil

A field experiment was conducted in the gneiss entisols to study the growth of the millet and soil nitrate with three nitrogen application rates(0,120 and 300 kg/hm2).In each main nitrogen treatments,two side treatments were set by combined application of 50% organic manure +50% urea(Y) and 100% urea(N) fertilization modes.The results showed that,under this experiment condition and compared with the control,all nitrogen treatments had significantly increased the yield of millet.When nitrogen rate was 120 kg/hm2,the yield of millet reached the highest;while the rate of N application increased to 300 kg/hm2,the millet yield did not significantly increased.The investigation of nitrate nitrogen distribution in 0-60 cm soil profile indicated that soil NO-3-N content increased with the increase of nitrogen fertilizer rate in the same mode of fertilization,especially the changes in the 0-40 cm soil profile were significant.Combined application of organic manure and urea could coordinate the provision of soil N and reduced the soil NO-3-N content significantly.