滴灌水分驱动穴施鸡粪对土壤酶活空间分布的影响

摘要

利用田间模拟试验,研究不同滴头位置和穴施鸡粪对土壤酶活性空间分布的影响,为大田施肥和灌溉技术提供理论依据.实验设置两个滴水位置:距肥料中心0和30 cm,施肥方式为穴施,将其组合为CM0(水肥位置一致)、CM30(滴头距肥料30 cm),以不施肥滴头正下方为对照(CK),测定了垂直深度(0 ～60 cm)和水平位置(10、20和30 cm)的土壤脲酶、蔗糖酶和碱性磷酸酶活性.结果表明,滴水和穴施鸡粪处理均能提高不同土层各水平位置土壤脲酶、蔗糖酶和碱性磷酸酶活性,且在0～20 cm土层各水平位置土壤酶活性有显著增加.3种酶活性均在5～15d达到最大值,随后逐渐降低.CM0和CK处理在整个处理周期中,各土层3种土壤酶活性均在水平10 cm酶活性最高,以滴头为中心向四周减小,而CM30在0～ 20 cm土层处理后5d脲酶和蔗糖酶活性水平30 cm最高,离滴头水平距离越远其活性就越小,随着处理时间延长,脲酶活性水平10 cm最高,离肥料水平距离越远其活性越小,蔗糖酶活性没有一致的规律,而碱性磷酸酶水平10和30 cm高于20 cm,20 ～ 40 cm土层脲酶活性在处理25 d后以肥料为中心向四周降低,碱性磷酸酶活性在整个处理周期中各水平30 cm最高.因此,水肥相同位置更有利于提高土壤脲酶、蔗糖酶和碱性磷酸酶活性,耕层离肥料水平10 cm位置土壤酶活性最高.%The objective of this field stimulation experiment was to study the effect of relative position of dripper and spot chicken manure on the spatial distribution of soil enzyme activities,in order to provide a theoretical basis and scientific guidance for field fertilization and irrigation.The experiment included two kinds of water position,i.e.0 cm and 30 cm away from the fertilizer application point.Manure application method was spot application.There were three treatments,CK-no fertilizer,CM0-water position and chicken manure in the same place,CM30-water position was 30 cm away from the fertilizer application point.Urease,invertase and alkaline phosphatase activities 10 cm,20 cm and 30 cm from the fertilizer position in horizontal direction and 60 cm in vertical direction from ground surface were investigated.The results showed that dripper and spot chicken manure application remarkably increased urease,invertase and alkaline phosphatase activities,especially in 0 ～ 20 cm soil layer,which arrived the maximum after 5 to 15 days and then decreased gradually.In soil profiles in control treatment and CM0 treatment,the enzyme activities were the highest at horizontal distances of 10 cm from the fertilizer application point and then decreased radially from the dripper.In the CM30 treatment,urease and invertase activities were the highest in 0 ～20 cm soil layer and at horizontal distances of 30 cm from the fertilizer application point after 5 days,and distributions of soil enzyme activities decreased with the distance from the dripper in soil profiles.With the incubation time prolonging,urease activity was the highest at horizontal 10 cm,and decreased from the fertilizer application point in soil profiles.Invertase activities had no the similar trend in the process,while alkaline phosphatase activity was higher at horizontal 10 cm and 30 cm than that at the horizontal 20 cm.In 20 ～40 cm soil layer,urease activity gradually decreased from fertilizer point after 25 days.Alkaline phosphatasc activity was the highest at horizontal 30 cm with time.In conclusion,in agricultural practice water and fertilizer in the same position helped to improve activities of urease,invertase and alkaline phosphatase,enzyme activities were the highest at 10 cm from the fertilizer application point in topsoil.