MANAGEMENT ZONES IN THE EVALUATION OF PHOSPHORUS AND POTASSIUM LEVELS IN THE SOIL AND ITS CORRELATION WITH THE IRRIGATED RICE YIELD

Abstract

The phosphorus participates in vital processes in plants, such as photosynthesis, respiration, energy storage and transfer, cell division and cell growth. The potassium acts in the activation of some enzymes and plays an important role in the balance of water in plants. This study aimed to correlate the levels of phosphorus and potassium with productivity in irrigated rice as well as assess the feasibility of precision farming use in irrigated rice area. This experiment was conducted for three seasons in succession crops: rice, soybean and, rice, in Santa Vitória of Palmar / RS / Brazil. We used an area of 22.18 ha, divided into 15 portions, which were the center point georeferenced. A soil sample were collected from each plot consists of 9 sub-samples, which were sent to the Soil Analysis Laboratory of UFPel. Income and fertility maps were generated using data of soil analysis and productivity and created management zones with different fertilizer to correct and standardize the phosphorus and potassium. These results show that: precision agriculture provided increase of soil fertility through the management areas of use; the use of management zones decreased variability in phosphorus and potassium in the plots studied the block; there was no correlation between the levels of phosphorus and potassium in the yield of irrigated rice.