To increase the fertility of dark brown chestnut soils in rice rotations the nutrient supply was studied at key plots. One-meter soil layer wasn’t saline; alkalinity was law. The content of exchangeable sodium in soil exchangeable complex was 7-12 %, exchangeable calcium – 52-67 %, exchangeable magnesium – above 30 %. The application of mineral fertilizers in rice rotations was analyzed in working conditions. In the course of three years (2008-2009) the average application at the 1st plot was N28P5K5, at the 2nd – N55, at the 3rd – 0,at the 4th– N5P5K5, at the 5th – N22, at the 6th– N23. In addition at the 1st plot the alfalfa as reclamation crop was grown for three years and at the 6th plot the reclamation field was in 2010, where the cultivation for weed control was carried out. It was established that the application of 100 kg/ha of ammonium nitrate for rice growth or 150 kg/ha of urea with the complex fertilizer (100 kg/ha nitrophoska) didn’t enable the accumulation and conservation of soil nutrients and introduction of the reclamation field in rice rotation wasn’t sufficient for optimization of nutrient regime in soils of rice rotation. After three years the supply of nitrates and mobile phosphorus in the 0-40 cm layer of dark brown chestnut soil at all key plots was low and medium except the fallow field where the supply was high during all years. The soils were high supplied with exchangeable potassium. The data on productivity at key plots indicate the insufficient supply with nutrients. The productivity doesn’t exceed 3.27 ton of feed units per hectare while the potential is higher than 5 ton of feed units per hectare.
