脲酶—硝化抑制剂缓释肥对不同土壤氮素释放特性及黄瓜NPK吸收利用的影响

为了提高黄瓜氮素利用率,减少氮肥对环境污染,采用恒温培养和土培试验研究了专用脲酶硝化双抑制剂缓释肥(CSRF1和CSRF2)在酸、碱、中性土壤中的氮素释放特性以及对黄瓜生长、NPK吸收利用的影响,其中缓释肥中包含抑制剂N-丁基硫代磷酰三胺(nBPT)、氢醌(HQ)、双氰胺(DCD)。结果表明:在酸、碱、中性3种不同土壤中,氮素释放累积量均表现为普通复合肥(OCF)商品缓释肥(MSRF)自制专用肥(CCF)自制专用脲酶硝化双抑制剂缓释肥1(CSRF1)自制专用脲酶硝化双抑制剂缓释肥2(CSRF2);不同施肥处理对于3种土壤类型影响下的氮素累积释放量顺序为碱性土最大,中性土次之,酸性土最小。铵态氮、硝态氮的累积量大小顺序也为碱性土最大,中性土次之,酸性土最小。不同形态氮在3种土壤中的累积释放量动态以应用一级动力学方程拟合最好(r=0.952**~0.993**)。通过一级动力学方程,反映了3种形态氮素的最大释放量N0值大小顺序:总N最大,NH_4~+-N次之,NO_3~--N最小,此结果与土壤中不同形态的氮素累积释放特性变化规律相一致。2种专用脲酶硝化双抑制剂缓释肥(CSRF1和CSRF2)显著提高了黄瓜产量(果实干物质量),较OCF、MSRF和CCF处理分别增加了59.1%,30.3%,33.8%(CSRF1)和46.2%,19.7%,22.9%(CSRF2)。与普通复合肥相比,2种专用脲酶硝化双抑制剂缓释肥处理的NPK相对养分利用效率增加了18.52%~24.20%(N),19.27%~20.02%(P),28.54%~35.69%(K)。相较于普通复合肥,黄瓜专用脲酶—硝化抑制剂缓释肥的施用能够延缓肥料中的氮素释放,提高黄瓜NPK养分利用率和黄瓜产量。

Effects of Slow-release Fertilizer Containing Urease-Nitrification Inhibitor on Nitrogen Release Characteristics in Different Soils and Uptake and Utilization of Nitrogen, Phosphorus, and Potassium by Cucumber

In order to improve nutrient utilization efficiency by cucumber and reduce the environmental pollution,special slow-release fertilizers containing urease inhibitor (NBPT),hydroquinone (HQ) and nitrification inhibitor (DCD) were produced according to the nutrient requirements of cucumber.Nitrogen release characteristics of two special slow-release fertilizers were studied by using the soil incubating method.Pot experiments were conducted to study the effects of slow-release fertilizers on yield,uptake and utilization rate of fertilizer and NPK by cucumber.The results showed that in three different soils,nitrogen release accumulation was in the order of ordinary compound fertilizer (OCF) ＞ commercial slow-release fertilizer (MSRF) ＞cucumber special compound fertilizer NO.1 (CCF) ＞ cucumber special slow-release fertilizer NO.2 (CSRF1)＞ cucumber special slow-release fertilizer (CSRF2),and nitrogen release accumulation in special slow release fertilizers (CSRF1 and CSRF2) were less than that of other fertilizer treatments.The amount of accumulated nitrogen release of different fertilizer treatments in three different soil types showed the order of alkaline soil ＞ neutral soil ＞ acid soil.Nitrogen accumulation amount of NH4+-N was more than that of NO3--N,possibly due to the nitrification inhibitor (DCD) could not only inhibit soil nitrification and denitrification processes,but could also inhibit soil denitrification process.The nitrification process was inhibited by nitrification inhibitors,and the nitrogen fertilizer would remain in the soil for a long time in the form of NH4+-N.Nitrogen accumulation amount of NH4+-N and NO3--N was also in the order of alkaline soil ＞ neutral soil ＞ acid soil.The dynamic release of different forms of nitrogen in three soils was fitted with a dynamic equation of the first order kinetic equation (r =0.952* *-0.993* *).Using the first order kinetic equation,the N0 value of the maximum release rate of different forms of nitrogen was in the order of total N ＞ NH4+-N ＞ NO3--N,which was consistent with the changes of the accumulation and release characteristics of different forms of nitrogen in the soil.The dynamic characteristics of nitrogen release by the equation were suitable for the prediction of the release properties and release characteristics of nitrogen in the soil.Two kinds of special slow release fertilizers (CSRF1 and CSRF2) significantly increased the yield of cucumber by59.1％,30.3％,33.8％ (CSRF1),and 46.2％,19.7％,22.9％ (CSRF2),compared with treatments of OCF,MSRF and CCF,respectively.Compared with common compound fertilizer,nutrient relative utilization efficiency of NPK in two kinds of special slow release fertilizer treatments was increased by 18.52％-24.20％ (N),19.27％-20.02％ (P),and 28.54％-35.69％ (K),respectively.Compared with traditional fertilizer,the use of two special slow-release fertilizers could effectively delay the N release in the soil,and increase the uptake of N,P,and K by cucumber plants and cucumber yield.