CHARACTERIZATION OF SOME AGRICULTURAL LANDS BASED ON AGROCHEMICAL INDICES. CASE STUDY IN THE AREA OF CENEI LOCALITY

Abstract

The study evaluated the fertility and spatial variability of some agricultural lands, in the area of Cenei locality, Timis county, Romania. The soil samples, representative for the studied agricultural lands, were taken from nine different locations. The soil reaction (pH, H2O), total nitrogen content (Nt), mobile potassium content (K, ppm) were considered and studied, and the degree of saturation in basic cations (V,%) was calculated. The soil reaction showed values between pH = 6.29 - 7.97 ±0.20, the degree of saturation in basic cations (V,%) had values between V = 74.80 - 100.00 ±3.13%, total nitrogen showed values between Nt = 0.11 - 0.35 ±0.03%, and the potassium content showed values between K = 275 - 390 ±15.49 ppm. High variability was recorded in the Nt index values (CVNt = 38.3598) and low variability in the soil reaction (CVpH = 8.3248). For the other soil indices studied, intermediate values were recorded, respectively CVV = 9.9760 for the degree of saturation in basic cations (V%), and CVK = 13.7177 in the case of mobile potassium content (Kmobil). The variation of the mobile K content in relation to the soil reaction (pH) was described by a polynomial equation of degree 2, equation (1), in statistical safety conditions, at the level of R2 = 0.779, p = 0.0121. Under PCA, PC1 explained 69.593% of variance, and PC2 explained 25.919% of variance. Cluster analysis facilitated the grouping of soil samples into two separate clusters, with three sub-clusters, under Coph. coeff. = 0.859.