Produtividade de soja em diferentes populações de plantas e sítios específicos de manejo em semeadura após a época indicada

Abstract

Soy constitutes one of the main crops of Brazilian and world agriculture, with important socio-economic role. In Brazil, currently, the soybean cultivars have increased production potential, and advanced technology for the production of grains and seeds. The productive potential of soy is genetically determined, but environmental factors are responsible for limiting the production. Factors such as height, geographic location, soil texture and fertility, sowing date and plant population are essential for the expression of genetic potential. The Precision Farming tools aim to support the rural activities, generating information of spatial and temporal variability that affects crop yields. We can treat differently parts of the same crop, using efficient and sustainable inputs of agricultural production. The aim of this study was to evaluate the soybean plant behavior in different plants population and management zones. Two soybean cultivars were used the NIDERA 6411 and TEC IRGA 6070, with plants population recommended is 31 to 28 plants per square meter, respectively. The plants population used were 25 and 50% for more and for less than recommended, totaling five treatments for each cultivar. The experimental design was completely randomized bifactorial in each management area. The following variables were evaluated: 1000 grain weight, yield, number of pods per plant, number of pods per square meter and plant height. The experiment was conducted in the experimental area of the Colégio Politécnico da UFSM, in 2015, after the recommended planting time, in the period known as off-season. The results of the variables were subjected to analysis of variance and regression and the means compared by Tukey test (p <0.05). In the high and average zones of management the cultivar NIDERA 6144 with plants population of 38 and 42 plants per square meter had the maximum technical efficiency. Already in low productivity zone, farming TEC IRGA 6070, in the amount of 47 plants per square meter, present the maximum technical efficiency. The population of plants inversely impacts the total number of pods per plant and directly the number of pods per square meter. Plant height is directly affected by the population of plants so that the higher the population, higher plant height, desired condition in planting after the recommended period.