Effect of soil PH on reasonable travel speed of mobile unit and lime application

Abstract

Precision agriculture, as a site-specific management concept, can increase profitability of crop production, improve the product quality and protect the environment. Applying the system of precision agriculture the soil, plant condition, fertilization demand, and fertility measures are taken into consideration. Using the data obtained, the technological parameters of agricultural machines are adjusted in a course of work. In such a way the consumption of fertilizers, lime, pesticides, fuel and time are optimised growing agricultural plants for food and feed. The soil pH value is a predictor of various chemical activities and a rough indicator of the plant availability of nutrients within the soil. Having the correct pH is crucial for the healthy plant growth as it will affect the amount of nutrients available to plants. The study was carried out using the mobile unit Veris 3150 MSP equipped with the Soil pH Manager system. After the assessment of accuracy of the pH maps formed, it can be stated that the reasonable travel speed of the mobile unit is 9 km·h-1. Increasing the speed, the unit records the measurement values in greater spaces, thus leaving small areas of field with different pH values unmarked. Traveling the unit at the speed of 3 km·h-1, it reached the work efficiency of 6.5 ± 0.5 ha·h-1 and at 12 km·h-1 – 26.5 ± 2.2 ha·h-1. The reliability of the soil acidity research conducted is proved by the linear correlation of soil pH identified using the Veris 3150 MSP and soil pH identified in the laboratory (R2 = 0.81). Selecting the lime rates according to the maps created by using the data of the unit, lime savings are about 40 %, compared to the liming based on the maps created on pH values determined in the laboratory. When liming is done according to the average of the laboratory data (equal to 500 kg·h-1 rate), some field areas are under-limed or over-limed