DMPP与尿素配施对新疆沙砾土壤氮素转化和葡萄叶片光合的影响

Effects of DMPP applied with urea on nitrogen transformation in gravel soil and photosynthesis of grape leaves in Xinjiang

研究尿素与硝化抑制剂3,4-二甲基吡唑磷酸盐(DMPP)混施对新疆沙砾土壤氮素转化及葡萄叶片光合的影响,以期为DMPP科学应用提供理论依据。以葡萄品种“赤霞珠”为供试作物,试验设不施肥、单施尿素以及在尿素中分别添加0.5%、1%、3%、5%的DMPP(含氮量的0.5%、1%、3%、5%),共6个处理,探讨不同浓度DMPP与尿素混施对土壤中NH_(4)^(+)-N、NO_(3)^(-)-N、硝化抑制率、p H值以及叶片SPAD值、净光合速率和胞间CO_(2)浓度等指标的影响。结果表明:施入尿素使土壤中NH_(4)^(+)-N含量增幅达150 mg/kg以上;与单施尿素相比,添加不同浓度的DMPP不仅可以延缓NH_(4)^(+)-N下降趋势,还能有效降低土壤中NO_(3)^(-)-N上升的趋势,但DMPP在0.5%~5%浓度范围内未发生明显的剂量效应,其中添加1%DMPP作用效果最显著;不同浓度的DMPP对土壤的硝化抑制率也不相同,1%DMPP在第14 d的抑制效果可达到49.60%;与不施肥相比,施入尿素可显著提高叶片净光合速率和SPAD值;利用主成分分析提取出的4个主成分可涵盖原始信息的84.146%,其中1%DMPP处理得分最高。综上所述,尿素与DMPP混施可显著抑制NH_(4)^(+)-N向NO_(3)^(-)-N转化,提高硝化抑制率,降低表观硝化率,使土壤中保持较高水平的NH_(4)^(+)-N含量,同时还可显著提高叶片净光合速率。不同浓度DMPP处理间有一定的显著差异,从经济效益和应用效果综合考虑,新疆沙砾土中以1%DMPP与尿素配施效果最佳。

The effects of urea and nitrification inhibitor 3,4-dimethylpyrazole phosphate(DMPP)combined application on nitrogen transformation in gravel soil and photosynthesis of grape leaves were studied in Xinjiang,in order to provide theoretical basis for the scientific application of DMPP.The grape variety Cabernet Sauvignon was used as the experimental crop,and six treatments were set up,including no fertilizer,urea alone,adding 0.5%,1%,3%,5%DMPP(0.5%,1%,3%,5%of nitrogen content)to urea,respectively.The effects of different concentrations of DMPP and urea on soil NH_(4)^(+)-N,NO_(3)^(-)-N,nitrification inhibition rate,pH value,leaf SPAD value,net photosynthetic rate and intercellular CO_(2)concentration were studied.The results showed that the content of NH_(4)^(+)-N in soil increased by more than 150 mg/kg when urea was applied,and the decreasing trend of NH_(4)^(+)-N was delayed when DMPP was added at different concentrations compared with urea alone,the increase of NO_(3)^(-)-N in soil could be reduced effectively,but DMPP had no obvious dose effect in the range of 0.5%-5%,and the effect of adding 1%DMPP was the most significant.The nitrification inhibition rate of different concentrations of DMPP was different,the inhibition rate of 1%DMPP was 49.60%on the 14th d,compared with the control group,the application of urea significantly increased the net photosynthetic rate and SPAD value of leaves.The 4 principal components extracted by principal component analysis covered 84.146%of the original information,of which 1%DMPP had the highest score.In conclusion,the mixed application of urea and DMPP can significantly inhibit the conversion of NH_(4)^(+)-N to NO_(3)^(-)-N,increase the nitrification inhibition rate,decrease the apparent nitrification rate,and maintain a high level of NH_(4)^(+)-N content in soil,at the same time,the net photosynthetic rate was increased significantly.Considering the economic benefit and application effect,1%DMPP combined with urea is the best in sandy gravel soil of Xinjiang.