Instrumento de coleta na amostragem de solo com agricultura de precisão

Abstract

The objective of this work was to evaluate the use of precision agriculture and of different soil collection instruments in soil sampling qualification. The study area has 21.83 ha and is located in Mangueirinha, in the Southwest of the State of Paraná. The crop used under no-tillage system (SPD) at 20 years, with soybean, corn, summer beans and wheat, barley, rye and winter oats, always with good productivity indexes. After the soybean harvest, in April 2016, soil sampling was performed using different numbers of fields and collection instruments: a) conventional model, dividing the area into 5 smaller areas using a cutting blade and 5 sub samples per Gleba; B) Precision Agriculture, with a sampling grid of 2 ha and 12 sub samples per gleba using screw thread; C) Precision Agriculture, with a sampling grid of 2 ha and 05 sub samples per gleba using a cutting blade. The soil was collected in the 0-10 cm layer and only the soil of the soybean interlayer was used to avoid interfering with the applied fertilization. Afterwards, the soil samples were sent to the soil laboratory of UTFPR-DV. They were air dried, milled and sieved in a 2.0 mm mesh. The soil samples were characterized when the pH values in H2O, CaCl2 and SMP, and C, P, K, according to the methodologies described in Tedesco et al. (1995). For agricultural areas under notillage system in the Southwest of PR, which has a high relief and soil variation, conventional sampling, even if it is done with a grid of 4.3 ha, half the area accepted, which is 10 ha, can not adequately characterize The heterogeneity of soil fertility. Soil sampling for chemical analyzes with grid of 02 ha is adequate to better characterize the heterogeneity of the agricultural areas under consolidated no - tillage system. The cutting blade is the most suitable instrument for soil sampling with precision agriculture, because soil profile variations up to 10 cm are more accurate. On the other hand, the screw feed gives more dynamism to soil sampling with precision agriculture, but collects less soil in depth, altering the values of P, K and MOS, as well as the application maps of inputs.