WAYS OF THE PRODUCTIVITY IMPROVING OF THE NARROW-LEAVED LUPIN IN THE CONDITIONS OF RADIOACTIVE CONTAMINATION OF POLISSIA REGION

Abstract

The authors have determined the influence of agrotechnical factors on the specific activity of radionuclide accumulation in the production of the narrow-leaved lupin.

Crop formation and the accumulation of radioactive elements in this crop create a complex combination of numerous physiological and biochemical life processes of vegetable organism; a huge variety of factors influences the intensity of this processing. The amount of intake of radioactive isotopes in agricultural production depends on soil and climatic conditions, peculiarities of plant biology, technological cultivating methods and other factors.

One of the major challenges of agriculture is to increase the production of livestock products. Its successful solution requires the creation of a stable fodder base. The main attention in plant cultivation and fodder production should be paid on the balanced protein feeding of the animals. Because of the protein shortage in one feeding unit, there is a 30–40 % feed overspending per unit of livestock production, and its cost is increased by 30–50 %. In conditions of radioactive contamination the agricultural producers should pay attention not only on the increase in the production of digestible protein but also feed getting that meets the standards of radionuclide content.

Therefore, the problem of protein in animal feed should be solved due to the expansion of planting acreage and production of the narrow-leaved lupin grain, which contains 30–35 % of protein. Per hectare of acreage we can get up to 25–30 quintals of grain, or 7.5–10.5 quintal/ha of digestible protein. Besides, the narrow-leaved lupin is a wonderful preceding herb, which provides favourable conditions for growing of the next crops.

Researches of Institute of agriculture of Polissia about distribution of radionuclides in the soil profile of different soil types have confirmed that the main amount of radioactive cesium in the remote period after the accident at Chornobyl nuclear power plant is concentrated in the topsoil. In particular, the average indexes of cesium-137 in the 0–20 cm layer of sod-podzolic sandy loam soil were 67,1–78,8 %, in the 20–30 cm horizon – 10.7–17.1 %, the remaining cesium was deeper than the 30-centimeter mark. In the 30–40 cm soil layer there was 4.1–11.3% content of cesium in the soil, in the 40–50 cm soil layer there was index 0,9–1,0 %. Below 50 cm index ranged downward from 1.5 to 0.4 %.

Researches in the development of new and improvement of existing technologies of cultivation of the narrow-leaved lupin at the maximum possible implementation of resource potential of varieties in the conditions of radioactive contamination of soils were carried out in 2008–2010 on sod-podzolic sandy loam soils with low indicators of nutrients, the acid reaction of soil solution and the activity of radionuclide contamination up to 182 kBq/m² (or 4.9 Ci/km²). Taking into account the weather conditions, these years were favourable for the growth and development of plants and yield formation of green mass and grains of the narrow-leaved lupin in pure sowing and mix.

The results of the researches of 2008–2010 show a significant impact of cultivation methods, seeding rate and fertilizer application on the level of grain yield and green mass of the narrow-leaved lupin and the level of radionuclide contamination of products.

The researches have confirmed that the productivity of the narrow-leaved lupin (the Winner variety) both in pure sowing and in the mix with oats, spring wheat and spring triticale in direct proportion depended on the studied agro-techniques. It is established that at a minimum seeding rate of the narrow-leaved lupin (0.6 million pieces/ha) in the variants without mineral fertilizers in the medium during three years 175.9 centner/ha of green mass and 13.1 centner/ha of grain were received. 1.5–2 times increasing of seeding rate influenced the yield of green mass and the narrow-leaved lupin grain that increased by 20-45 %.

In conditions of Polissia in the contaminated areas with a contamination density of soil to 5 Ci/km and according to the cultivation technology of the narrow-leaved lupin that provides the seeding to 1.2 million pieces/ha and a complete fertilization dose of  N₃₀Р₆₀К₆₀, there is an ability to get 20,0–27,0 centner/ha of grain with a specific activity of radiocesium 228–236 Bq/kg, that do not exceed a permissible level (PL-2006) 250 Bq/kg. The phosphorus-potassium fertilizers in the dose of Р₆₀К₆₀ contribute to the decrease in the activity of radiocesium in grain and green mass by 24–27 %.

Introduction of mixed sowing of the narrow-leaved lupin with forage cultures at the seeding rate 0.9 million pieces/ha of legumes and 2.5 million pieces/ha of cereals on the background of a complete fertilization dose of N₃₀Р₆₀К₆₀ contributed to the production of 358,0–386,3 centners of balanced protein-carbohydrate green mass and 35,7–39,6 centner/ha of grain and decreased the content of radiocesium in 1.7–1.9 times in the obtained products compared to the pure sowing of the narrow-leaved lupin.

The narrow-leaved lupin, which is a valuable forage culture, can be used for animals` feeding in locations of radionuclide contamination of soil after the accident in Chernobyl.