长期沼肥深施对果园土壤养分和酶活性的影响

Effects of Deep Application of Long-term Biogas Fertilizer on Soil Nutrients and Enzyme Activities in Orchard

针对西南丘陵区柑橘果园化肥导致的土壤质量下降、生态环境逐年恶化等现状,通过施肥方式与耕作方式的改进与协作,研究了长期不同量沼肥深施对0~60 cm土层主要养分含量和酶活性的影响。结果表明:沼肥处理均能显著提升表层土壤(0~20 cm土层)有机质、全N、全P含量和深层土壤(40~60 cm土层)全K含量。其中T5处理效果最好,显著提高了各土层养分含量,由浅层至深层,有机质、全N和全P含量分别较CK提高了62.4%、30.3%、63.1%;40.0%、23.5%、44.1%;122.0%、36.9%、72.9%。沼肥深施对土壤酶活性影响较大,能显著提升0~40 cm土层蔗糖酶活性。T3、T5处理还能分别显著提升0~20、20~40、40~60 cm土层脲酶活性、0~20、20~40 cm土层过氧化氢酶活性以及20~40、40~60 cm土层碱性磷酸酶活性。综上所述,柑橘果园高量沼肥深施能够实现养分向土壤深层输送,改善土壤质量,为沼肥部分或全部替代化肥在果园中的应用提供了参考,有助于实现土壤生态环境良性循环。

In view of the current situation of Soil degradation and its ecological environment deterioration caused by chemical fertilizer in citrus orchards in southwest hilly region year by year,the effects of different amount of long-term biogas fertilizer deep application on main nutrient contents and enzyme activities in 0~60 cm soil layer were studied by the improvement and cooperation of fertilization methods and tillage methods.The results showed that soil organic matter content,total N content and total P content were significant increased in 0~20 cm soil layer and the total K content was increased in 40~60 cm soil layer by deep application of biogas fertilizer.Among them,T5 had the best effect.The soil organic matter content,total N content and total P content of each soil layer were significantly increased by 62.4%,30.3%and 63.1%in 0~20 cm soil layer,40.0%,23.5%and 44.1%in 20~40 cm soil layer,and 122.0%,36.9%and 72.9%40~60 cm soil layer,respectively.The soil enzyme activities also were affected by deep application of biogas fertilizer.The activity of invertase in 0~40 cm soil layer was significantly increased by deep application of biogas fertilizer.Compare with CK,soil urease activity in 0~20 cm and 40~60 cm soil layer,soil catalase activity in 0~20 cm and 20~40 cm soil layer and soil alkaline phosphatase activity in 20~60 cm and 40~60 cm were increased in T3 and T5.In conclusion,deep application of biogas fertilizer in citrus orchards could transport nutrients to the deep soil,promote the absorption of nutrients by roots and realize the virtuous cycle of soil ecological environment.