Abstract only

Soil fertility modeling is the most promising among the modern methods of determining the tactics of soil fertility management. Experience of the recent 50-60 years suggests that along with securing high crop yields, environment protection and maintenance of ecological purity of soils are the priorities for any farming system. Unfortunately, agrochemical service companies that are not well-controlled by the government and do not follow scientifically grounded recommendations provide farmers with low quality services. Soil fertilization is carried out without conducting soil tests and irrespectively of actual availability of nutrient elements. This practice has led to the disturbance of the natural balance of the nutrient elements. Many nutrient elements have converted to an insoluble condition and have become, therefore, inaccessible to plants. Besides, accumulation of undesirable "toxic ballast" in soils resulted in lower activity of soil micro-biocenosis, which has upset soil fertility and its biological activity. One of the most difficult and complicated issues in soil fertility modeling is the modeling of its nutritive regime. Agricultural crops may uptake not only nutrients that are readily assimilable by plants, but also other nutrient elements that can convert into such readily assimilable forms and become available for plants. Information reflecting the levels of availability of three reserve (immediate, inter- mediate and potential) forms of nutrient elements is very useful from the practical point of view and should be included in the land documents and agrochemical maps due to the following advantages: .This will extend validity of the land and agrochemical maps to 20-25 years and save much resources and time required for updating these documents every 5 years; .Fertilization rates will be estimated more precisely and the amount of the substances excee- ding the standards and contributing to the toxicity will be reduced; .Spending of costly mineral fertilizers will be reduced. Neglecting of these principies may lead to ex- cessive fertilizer applications and consequent envi- ronmental and soil contamination. Filed data for the study is obtained at the demonstration field in Goranboy district established by the project implemented jointly by CIMMYT and Ganja Agribusiness Association (GABA). Project implementation agenda includes modeling of fertility of soils of the trial plots that are cultivated under wheat, crop management and yield forecast. The experiment was conducted on light-chestnut soils near the Nizami village of Goranboy district and include 5 bread wheat varieties (Azametli-95, Nurlu- 99, Lutescens-85, Ekinchi-84 and Krasota), 2 durum wheat varieties (Garabag, Bereketli-95), 2 triticale varieties (Samur, and Shirvan) and one barley variety (Garabag-22), each of which were planted to a 0.1 ha plot. Besides, 2 hectares of alfalfa were planted. It is known that involvement of a legume crop in rotation with wheat increases soil fertility and makes the nutrient elements readily available for plants. The reserve forms of the different nutrient elements in the light-chestnut soil samples taken before sowing and at the different stages of plant development were studied in the laboratory condi- tions. According to the obtained initial results, diffe- rences in the level of assimilability of nutrient reser- ve forms in different wheat varieties were recorded. In Ganja-Basar region, for the first time in the Republic, through modeling the nutritive regime of soil for the prolonged period (15-50 years), the factors enabling long-term controlling and prediction of soil fertility properties are determined. By studying the transformation of minerals in the soils and distribution of nutrient elements in the three reserve forms (immediate, intermediate and potential), new scientifically grounded principles are proposed for soil fertility management and soil- agrochemical documentation development.

English

0409|AGRIS 0401|AL-Wheat Program

Juan Carlos Mendieta

CIMMYT Publications Collection