Askhad Khasrethovich Sheudzhen, Oksana Aleksandrovna Gutorova, Hazret Dovletovich Hurum, Galina Fedorovna Petrik and Tatyana Nikolaevna Doroshenko
Kuban State Agrarian University, Kalinina Street, 13, Krasnodar, 350044, Russian Federation
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(Received : September 15, 2020; Accepted : November 14, 2020)
This paper aimed at studying the dynamics of the nutrient contents in the soils of rice crop rotation fields and fields with continuous rice cultivation. The studies were carried out on meadow-chernozemic and meadow-swamp soils of the Maryano-Cheburgolsky irrigated massif in the Krasnoarmeysky district of the Krasnodar region (Russia). Soil samples were taken by rice vegetation phases to determine the content of exchangeable ammonium and active forms of phosphorus and potassium. The development of recovery processes after the flooding of soils in rice fields contributed to the activation of available mineral nutrients for rice plants. The maximum content of ammonium nitrogen (1.90-2.36 mg/100 g), active phosphorus (9.88-10.45 mg/100 g) and potassium (33.23-39.50 mg/100 d) was noted during the germination, flowering, and tillering phases of rice, respectively. The use of perennial grasses in rice crop rotation contributed to the enrichment of soils with nutrients during their stay in a non-flooded state (0.65-0.70 mg NH4/100 g; 5.29-8.10 mg P2O5/100 g; 19.85-23.61 mg K2O/100 g). The use of meadow chernozemic soil for continuous rice cultivation during 80 years led to a decrease in their content compared to rice crop rotation fields (0.52 mg NH4 /100 g; 2.71 mg P2O5 /100 g; 16.64 mg K2O/100 g). Over the past 15 years (from 2002 to 2017) of continuous rice cultivation, the content of ammonium nitrogen and active potassium decreased from 0.72-1.19 to 0.38-0.67 mg/100 g and 15.24-21.68 to 13.03-18.72 mg/100 g, respectively, depending on the vegetation phase of the plants. Compared with the rice crop rotation fields, the yield of rice in permanent cultivation fields was 3.5-4.0 times (42.2-54.6 centners/ha) lower.
Key words : : Meadow-chernozemic soil, meadow-swamp soil, nutrients, rice crop rotation, permanent
rice cultivation, yield