Cycles,Nitrogen Budget,and Sustainability of Agroecosystems after Applying Organic Fertilizers (Labeled with 15N)

Eurasian Soil Science - The nitrogen of organic fertilizers contributes to stabilization of nitrogen cycles and sustainable development of agroecosystems. The application of green manure biomass as...     

Nitrogen Flows in Agrocenosis of Winter Wheat Under Conditions of Different Reactions of Typical Chernozem Medium (Based on Application of <Superscript>15</Superscript>N)

It is shown that an increase in winter wheat on typical chernozem characterized by the acid reaction of the soil medium leads to a decrease in grain yield to 30% and straw weight to 25%. The crop reached the maximum level after introducing urea and manure wastes (the yield gain was 199% in neutral soil and 165% in acidic soil). The improvement of plant nitrogen nutrition by introducing fertilizers led to an increase in the protein content in grain by 1.2 times on both soils; at the same time, the protein content was 1.1 times lower in acidic soil than in the neutral one. The maximum content of protein in winter wheat grain accumulated after both types of fertilizers were applied on neutral soil; the use of manure wastes alone decreased the protein content in grain. It has been revealed that a decrease in the yield of grain and a decrease in the content of crude protein in this grain after acidification of typical chernozem is due to a decrease in the amount of mineral nitrogen in soil and an increase in its gaseous losses. The pattern of nitrogen transformation in soil, as well as the availability of nitrogen for the plants, varied as the reaction of the medium changed. In acidic soil, the consumption of mineral fertilizer nitrogen and manure wastes by the plants decreased by 12–13% and the consumption of soil nitrogen decreased by 45%. The effect of wastes decreased the consumption of urea nitrogen by 49% (neutral soil) and by 69% (acidic soil). The consumption of fertilizer nitrogen by the plants decreased by 12–15% after acidifying typical chernozem and by 12–17% after immobilizing this type of chernozem and increased gaseous losses by 18–81%. It has been concluded that the agrophytocenosis of winter wheat maintains the ecological balance (homeostasis) when wastes from a pig-breeding complex are used and is exposed to stress when urea is applied in acid chernozem. Soil acidification decreased the resistance of agrophytocenosis to the level that is observed when manure wastes were applied and to adaptive depletion when urea was used.     

Features of nitrogen microorganism assimilation of perennial grasses phytomass in soils of a different degree of erosion

In the sod-podzolic soil subject to water erosion, nitrogen incorporation of perennial grasses (clover, thimophy) is reduced in microbial biomass. When applying perennial grasses phytomass, nitrogen is lost by 4.6 times from the noneroded soil and by 1.5 times less from the eroded soil as compared to applying ammonium sulfate.     

Endophytic bacteria of woody plants as the basis of complex microbial preparations for agriculture and forestry

The literature review focuses on endophytic bacteria inhabiting woody plants. Endophytic bacteria for genera Pseudomonas, Bacillus, Paenibacillus, Burkholderia, and Erwina are shown to be found in almost all woody tissues. In additional, endophytic bacteria have been found in reproductive plant organs. It is shown that endophytic bacteria have functional properties that are useful for host plants: the ability to fix atmospheric nitrogen, produce growth simulating and biocontrol substances, and to induce systemic resistane of plants to biotic and abiotic stresses. Endophytic bacteria are a major part of the microbiome of woody plants, possess valuable functional properties of host plants, and are a promising biotechnological resource for the development of complex microbial preparations for agriculture and forestry.     

Effect of ecological factors on ammonifying and nitrifying capacity of sod-podzolic soil

The optimal conditions for nitrifying and ammonifying processes of sod-podzolic soil in the eastern part of the Non-Chernozem Zone are given: temperature 15°C, soil moisture content 20–25%, soil density 1.1 g/cm³, and neutral pH value.     

Evaluation of the efficiency of spring wheat and vetch mixed crops

It is shown that a comparative evaluation of the biological efficiency and intensity of competitive relations in cereal (spring wheat) and pulse (spring vetch) mixed crops is the most complete and accurate in yield of the main product (grain, dry matter) and biological yield (grain + straw + chaff, dry matter)     

Change in quality parameters for brewing barley grain at fractionation

The change in the main quality parameters for brewing barley grain at fractionation has been studied to develop the method of their regulation. The barley grain of different fractions is proven unequal in the biochemical composition and the technological quality. The fractionation of the grain samples collected from the large homogenous grain bulks and the relevant analyses can provide the possibility to determine a wide range of quality parameters for the specific fractions and their grain-size dependencies. The basic parameters for the technological quality of barley grain in a certain bulk may be changed (raised or lowered) to the regulatory standards or the standards that consumers demand with the use of the appropriate top and (or) bottom sieve installation in the grain cleaning machines of secondary cleaning.     

Change in Quality Parameters of Hulled Oats Grain at Fractionation

The changes in the main indices for grain quality of hulled oats at fractionation for the development of the method for their regulation were studied. It was shown that the grains of various fractions of hulled oats is not equal by biochemical composition and technological qualities. Fractionation of the grain samples collected from homogeneous large batches of oats and carrying out of corresponding analyses allowed the determination of a broad range of quality indices of individual fractions and their dependence on the thickness of the caryopsis. Then, by the correct selection and installation of top and (or) bottom sieves on seed cleaning machines of secondary cleaning, one can change (increase or decrease) the basic quality indices of a batch of grain from hulled oats up to values regulated by the State Standard or standards demanded by the consumer.     

Nitrogen utilization by oat plants in an Agroecosystem

It is found that a more environmentally efficient nitrogen balance on sod-podzolic soil of a slope develops after incorporation of clover biomass. Oat plants utilize 37% of clover N on the crest-close slope and 25% in its lower part; in this case, 55 and 50% N, respectively, become soil-stabilized; 8 and 25% N are lost. Minimum nitrogen quantity is used up by oats from organic sources after incorporating timothy biomass; the maximum of 69 and 59% become soil-stabilized, its highest losses reaching 14–27%.     

Fertilizer Nitrogen Use by Spring Triticale and Spring Wheat on Dark-Chestnut Soil of the Dry Steppe Zone of Kazakhstan

In an experiment with the use of a stable isotope of nitrogen ¹⁵N, the impact of fertilizers on grain yield of spring wheat and spring triticale on the dark chestnut soil in the dry steppe zone of Northern Kazakhstan was estimated. The maximum yield of spring wheat grain was obtained when introducing N₆₀ before sowing and that of spring triticale (2.2 times higher) when introducing N₆₀ in equal parts before sowing and during tillering. The effect of nitrogen fertilizer on yield of both the crops is more efficient compared to phosphate fertilizers. Both the crops used 30% of the introduced doses of fertilizer nitrogen for yield formation; 32% was fixed in the soil under spring wheat, 34% under spring triticale, and gaseous losses of nitrogen fertilizer were 38% and 36%, respectively. The maximum use of nitrogen fertilizer on yield formation (41–42%) is typical of both the crops when introducing N₃₀ before sowing both against the background with and without phosphorus. As a result of better nitrogen use by plants, its gaseous losses fell to 15–26%. It is noted that, both in case of P₀ and P₆₀, levels of fertilizer nitrogen use decreased almost twofold, from 41–42 to 23–28%, when the nitrogen fertilizer dose was doubled. Fractional introduction of N₆₀ by equal parts before sowing and during tillering hardly affected the amount of nitrogen fertilizer used by plants of both the crops for yield formation. The use of N₃₀ during tillering compared to a similar dose before sowing reduced the factor of fertilizer use by plants.