SOIL MICROBIOLOGICAL ACTIVITY AND PRODUCTIVITY OF MAIZE FODDER WITH LEGUMES AND MANURE DOSES

ABSTRACT Maize is an important cereal and it is widely consumed in the world, both as food for humans and animals. Nitrogen (N) is a nutrient required in large quantities by maize, but unfortunately, soils are limited in meeting this need. Nodulating legumes can serve as a source of Nitrogen, because they are symbiotically associated with bacteria capable of fixing atmospheric N. Another important source of this nutrient is cattle manure, which is widely used in agriculture. The objective of the present study was to evaluate the effect of using legumes and cattle manure on the production as well as the microbial and biochemical quality of the soil used for maize cultivation. The experiment was conducted using a randomized complete block design, in a sub-subdivided plot scheme [(2x4) +2], two leguminous plants (pigeon pea and macassar bean), four doses of cattle manure (0, 20, 40 and 60 t ha-1) and two controls; one with mineral fertilization and the other cultivated without the use of fertilizers. Treatment using a manure dose of 60t ha-1 and pigeon pea legume, recorded higher dry mass production per plant. The increase in manure doses was directly proportional to the length and weight of the cobs for the two legumes. The enzymatic activities were affected by the different doses and legumes, with greater results being recorded at the 60 t ha-1 dose with the macassar legume. The use of legumes with manure improved maize production as well as the microbiological and biochemical quality of soils.

摘要 玉米是重要的谷类作物，在全球范围内被广泛用作人类及动物的食粮。氮（Nitrogen, N）是玉米需求量极大的营养元素，但土壤所能提供的氮素往往难以满足其生长需求。结瘤豆科植物（nodulating legumes）可作为氮素来源，因其与能够固定大气氮的细菌形成共生关系。另一重要的氮素来源是牛粪肥，在农业生产中应用广泛。本研究旨在评估施用豆科植物与牛粪肥对玉米种植的产量以及土壤微生物学与生物化学品质的影响。试验采用随机完全区组设计（randomized complete block design），设置裂裂区小区方案[(2×4)+2]，包含2种豆科植物（木豆（pigeon pea）、macassar bean）、4个牛粪肥施用量梯度（0、20、40、60 t ha⁻¹）以及2个对照组：其一施用矿物化肥，其二不施用任何肥料。其中，施用60 t ha⁻¹牛粪肥配合木豆的处理组，单株干物质产量最高。对于两种豆科植物而言，牛粪肥施用量的提升与玉米果穗的长度、重量呈正相关。不同施用量及豆科植物种类均会对土壤酶活性产生影响，当施用量为60 t ha⁻¹且搭配macassar bean时，酶活性表现最优。施用豆科植物配合牛粪肥，可同时提升玉米产量与土壤的微生物学及生物化学品质。