Yield and export of nutrients in chicken manure-fertilized snap bean

ABSTRACT

The analysis of nutrient accumulation and exportation in snap bean is fundamental to help develop a more sustainable fertilization, since defining the organic fertilizer doses needed for snap bean cultivation based only on an estimated maximum production does not guarantee that soil fertility is maintained. The objective of this study was to evaluate the effect of chicken manure fertilizer on snap bean yield, accumulation, and nutrient exportation. The experiment was arranged in a randomized block design, with five chicken manure fertilizer doses (0;5;10;20, and 40 t ha^-1) and four repetitions. Higher P and Mg contents were verified in the leaves following application of chicken manure fertilizer dose of 40 t ha^-1.Maximum pod length was 14.47 cm, estimated with chicken manure fertilizer dose of 33.33 t ha^-1. The highest diameter, number of pods per plant, and pod yield were verified at the highest chicken manure fertilizer dose applied (40 t ha^-1).In relative terms, i.e., total exported in relation to total extracted of the aerial part, phosphorus is the most exported nutrient in the pods, at an average of 58%, followed by N (55%), K (43%), Mg (40%), S (38%), and Ca (17%). Although a large amount of Ca accumulation (31.3 kg ha^-1) was verified at the highest dose, only 13% of it was exported by the pods. Chicken manure fertilizer supplies the essential nutrients and increases pod yield from 7.2 to 16.3 t ha^-1, when comparing between no fertilization and the highest chicken manure fertilizer dose. The cultural residues of snap beans are an important source of Ca and Mg, with the following nutrient amounts (kg ha^-1) N (51.4); P (5.1);K (27.6); Ca (27.1); Mg (8.2); and S (5.1) being obtained at the highest chicken manure fertilizer dose applied (40 t ha^-1), and which can return to soil through incorporation by the plants.

Key words:
Phaseolus vulgaris; nutrient content; organic cultivation; plant nutrition