METHOD FOR DETERMINING FARM CROP DEMAND OF NITROGENOUS FERTILIZER Russian patent published in 2003 - IPC

FIELD: agriculture. SUBSTANCE: method involves annually determining nitrate nitrogen (Nn) in 0-20 cm and 20-40 cm thick soil layer and humus (A20) in 0-20 cm thick soil layer once per crop rotation and determining farm crop demand (H) of nitrogenous fertilizer in accordance with formula: H={Np-(Nn20. d20+Nn40. d40). 2-Ts. 0.00075. A20.0.579. d20.2,000,000/100. cd/100/R (C/N)-1.55. Y.100.0.5.0.015.0.17}. kW, where Np is coefficient equivalent to availability of mineral nitrogen for crop in soil by sowing date; Nn20 and Nn40 are content of nitrate nitrogen in 0-20 cm and 20-40 cm thick layers, respectively; d20 and d40 are volumetric weight of soil in 0-20 cm and 20-40 cm thick layers, respectively; R(C/N) is C/N ratio in soil organic substance of 0-20 cm thick layer; A20 is content of humus in 0-20 cm thick layer; cd is coefficient of depth of humus accumulating soil layer and content of humus therein; Ts is total of positive average daily soil temperatures for period of from autumn (sampling date) to spring (sowing date); 0.00075 is percentage amount of mineralized carbon of soil organic substance per day at soil temperature of 1 C of carbon content in soil organic substance; 0.007 is average nitrogen content in mortmass; 0.17 is share of decomposing mortmass from autumn to spring; 0.5 is coefficient for recalculation of cereal straw weight per year of samples into amount of mortmass in autumn; Y is precursor cereal crop grain yield, centner/hectare; 1.55 is coefficient for recalculation of grain weight into cereal straw weight; kw is complex coefficient for evaluating heat and moisture capacity of growing period. Method is used for determining demand of soil in nitrogenous fertilizer needed for growing of cereals, industrial or fodder crops, and potato. EFFECT: reduced labor intensity, increased efficiency in precise determining of nitrogenous fertilizer demand for farm crops. 1 dwg, 1 tbl