Variabilidade espacial da produtividade e da qualidade de sementes de trigo e soja produzidas em sucessão sob sistema de plantio direto

Abstract

The objective of this work was to correlate soil attributes with yield and physiological quality of wheat and soybean seeds. In the first paper the objective was to study the linear correlations and the spatial distribution between the attributes of the soil and the yield and the physiological quality of wheat seeds. In the second paper the objective was to correlate attributes of soil, plant and physiological quality of seeds in a field of soybean seed production. In the third paper, the objective was to evaluate the temporal variability of soil nutrients between successive wheat and soybean seed crops, and the spatial distribution of the yield of the two crops relating to the soil nutrient spatialization. The work was performed in a seed production field at the company Granello Seeds in an area totaling 41 hectares, where wheat and soybean seeds were produced in the 2013 and 2013/2014 crops season. The evaluations were carried out from a georeferenced sampling grid with spacing of 100 x 100 meters. Germination, first germination count, accelerated aging, seedling emergence, electrical conductivity, and yield for wheat and soybean seeds were evaluated. In wheat, the content of chlorophyll A in the leaf, number of ears, hectolitric weight and protein content in the seed were evaluated. In soybean, it was observed number of branches per plant, number of pods per plant, number of seeds per plant and plant height. The soil attributes evaluated were calcium, magnesium, phosphorus, potassium, sulfur, iron, aluminum, zinc, organic matter, pH, cation exchange capacity, SMP index, soil penetration, percentages of sand, silt and clay. The analysis of spatial distribution maps of soil nutrients is a tool that can contribute to farmers' decision making in the management of crop fertilizing, aiming to improve seed productivity and quality.