ISSN: 1659-2751



Evaluation of the Organic Fertilizers produced at EARTH University in an Associative System of Corn Soybean


The effect of organic fertilizers produced at EARTH University was evaluated in a crop association of corn and soybean. The study was conducted using four organic fertilizer treatments: compost, EM-compost, a 50:50 mixture of EM-compost and compost, and green forage of mountain immortelle (Erythrina poeppigiana). An experimental completely randomized, split-plot design, with four repetitions, was used. The nutritional conditions of the soil were evaluated at the beginning and end of the crop cycle. Quantitative characteristics in the corn and soybean were evaluated. The cost of production and yield for each treatment was determined. In relation to the chemical analysis of the soil at the end of the crop cycle, the three compost treatments showed an increase in the extractable acidity of 0.5 cmol(+)/L compared with the initial value. The green forage treatment increased the extractable acidity by 1.0 cmol(+)/L. In terms of macro nutrients, N in the soil was higher (0.78 %) at the beginning of the crop cycle than at the end. P was higher in all treatments at the end of the crop cycle. K only had a higher percentage in the EM-compost and EM-compost and compost treatments. The C:N ratio at both the beginning and end of the crop cycle was less than 20:1; therefore N was available to the plants throughout the cycle. Statistically significant differences were found between treatments (p<0.01) for the quantitative descriptors of the corn plants. The EM-compost and compost treatment showed the lowest values in relation with the height of the plant, diameter of the stalk as well as for the number and size of the leaves, at the end of the crop cycle. Regarding the fruit, for both crops, the green forage treatment showed the lowest values for all the variables studied. The cost of production for the green forage treatment was lower than for the other treatments; however, it also produced the lowest yield for both crops..

Key words: compost, associated crops, EM-compost, Erythrina poeppigiana, corn, soybean.

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