Yields of Buckwheat and Groundnut and Dynamics of Soil Nutrients in a Rotation Fertilized Mainly with Cow Dung Pellet Compost.

Abstract

Groundnut (Arachis hypogaea) grown without fertilizer was grown in rotation with autumn-sown and spring-sown buckwheat (Fagopyrum esulentum) for 4 years. Groundnut harvest residues were incorporated to the soil, and then cow dung pellet compost was supplied by either full width application (FA) at 1 kg/m² or stripe application (SA) at 0.5 kg/m² in planting rows, before the buckwheat crop was sown. The growth and grain yields of buckwheat grown in the FA and SA plots and the plot with a standard amount of inorganic fertilizer (IF) were compared. The growth and yield of groundnuts tended to be larger in both compost plots than in the IF plot over the 4 years. The compost released more N and P per kilogram than IF. As a result, the growth and grain yield of the autumn-sown buckwheat in both compost plots were the same as those in the IF plot over the 4 years. The spring-sown buckwheat received an application of half the IF quantity in the FA plot and one-third of it in the SA plot. The growth and grain yield of the spring-sown buckwheat in both compost plots were similar to those in the IF plot. Continuous application of compost in the field experiment improved the fertility over time. The amount of available N at sowing was significantly greater in the FA and SA plots than in the IF plot, and the inorganic N content remained consistently higher in the FA and SA plots until harvest.