Biological and Ecological Characteristics of Rape Cultivation under Conditions of Suntar Agrolandscape

Abstract

The article describes the questions of spring rape production for stabilization of forage base for cattle breeding in the Republic of Sakha (Yakutia). The effect of mineral fertilizers on rape growth, development and green mass gain has been studied experimentally on frozen soils of Suntar agrolandscape in Western Yakutia. With taking into account natural and climatic conditions and biological productivity of the Suntar agrolandscape, the optimal rate of mineral fertilizers was estimated to gain a maximal rape green mass production (up to 248.3 centner/ha at N135P120 K120). The daily apical growth during flowering stage was proved to make up 2.2–2.7 cm regardless different rates of mineral nutrition. The following developmental stages showed stable linear increment up to 4.2–4.7 cm. Applying N180P120K120 resulted in maximal plant height up to 95 cm. Higher nutrition rates (N180P120K120) increased daily yield during the last developmental stages (flowering-pod formation). At that, daily green mass gain during the flowering-pod formation stages made up 54 g/m2 in average. Having applied N135P120 K120 to rape plantings, the maximal green mass gain was provided by 1 kg of nitrogen (up to 97.7 c/ha), phosphorus (up to 76 c/ha), and potassium (up to 70.3 c/ha). Specified optimal rates of fertilizers in Suntar agrolandscape are recommended for large-scale implementation in field forage production of spring rape green mass in Central Yakutia.