Estimation of the initial agrochemical index of farmland fertility by average weighted integral indices

Abstract

An assessment of the initial state of farmland fertility on the basis of an agrochemical soil analysis makes it possible to determine the direction of the complex of land reclamation measures that help to increase soil fertility. The need for this is due to the development of degradation processes in the soil, as a result of which the reserves of soil humus and essential nutrients that are necessary for the productive development of plants have decreased. The authors of the article propose an assessment of the initial fertility of farmland by the main agrochemical parameters (humus G, nitrogen N, phosphorus P, potassium K and hydrolytic acidity Hg.). The evaluation analysis is based on the «integral soil fertility index» proposed by S.A. Pegov and P.M. Khomyakov. The agrochemical laboratory in the APC Kolkhoz «Pamyat Lenina» conducted analysis of the initial weighted average agrochemical state of farmland on the basis of soil survey data, and according to the results established the indicators of the initial and maximum fertility index (SG, SNPK, SНг and generalized soil index - S). With maximum reserves of humus G = 600 t / ha, and in the absence of a shortage of basic mineral nutrition elements (N: P: K = 1: 0.5: 1) and hydrolytic acidity Hg = 1, the components of the soil fertility index are: SG = 6.4 units, SNPK = 8.5 units, SНг = 5.1 units, and the generalized soil index S = 20 units. An analysis of the initial state of arable land clearly identifies a deficiency in two components of fertility: SG = 2.93 units, SNPK = 3.06 units, which is 46.3 % and 58.6 % of the maximum. Set of ameliorative measures should be directed to an increase in the humus reserves in the soil, as a result, additional supply of soil biomass; increasing doses of mineral fertilizers, bringing the ratio of mineral nutrients to the optimum. To determine the trend of changes in the state of farmland, it is necessary to conduct its forecasting.

Keywords

• fertility
• humus
• soil index
• farmland
• initial state
• dynamics
• forecasting
• nutrients