Influence of reducing tillage on the content of nutrition elements in chernozem ordinary

Abstract

Crop productivity depends on the nutritional regime of the soil. Factors that affect the content of nutrients in the soil include various tillage systems. The article presents the results of studies of the effect of minimizing tillage in the Northern Steppe of Ukraine on the content of basic nutrients. In soil samples, the content of nitrate nitrogen was determined by potentiometric ammonia nitrogen with Nessler's reagent, mobile phosphates and exchangeable potassium according to Chirikov. Changes in the redistribution of their content in the 0-30 sm layer of chernozem ordinary with minimal and zero tillage were established. The highest degree of differentiation was noted for nitrate nitrogen: an increase in nitrates in a layer of 0-10 sm relative to a layer of 1020 sm was 28.3% for minimal processing and 42.3% for zero; relative to the 20-30 sm layer, respectively 46.5 and 92.2%. A decrease in the content of nitrate nitrogen by 6.014.5%, an increase in mobile forms of phosphorus by 9.8% and exchange potassium by 4.2% while minimizing tillage was established.  Keywords: minimization of tillage, zero tillage, minimal tillage, plowing, ordinary chernozem, plant nutrients
 
Actuality. In conditions of changes of climate and growing threats to the degradation processes in soils, soil protection technologies of cultivating crops that reduce the intensity of soil cultivation and the use of the protective role of plant residues deserve special attention. The nutrient regime of the soil is determined by the content of various forms of nutrients and their microbiological activity. It is therefore vital question of research impact in minimizing tillage, including zero tillage technology content in batteries along the ground. 
Aim of research - to determine the effect of plowing, minimum and zero tillage on the content of mobile forms of nutruents in 0-30 sm layer of humus of chernozem ordinary.  Materials and methods of research. Field studies were conducted in an experiment in the joint-stock company "Agro-Soyuz" of the Dnipropetrovsk region under barley. The experiment included three options for cultivation in plowing at 2325 sm, minimum tillage to 4-5 sm no-tillage. The fertilizer system is the same for all variants of work - N 60 P 40 K 40 .  The soil of the experimental plot is chernozem ordinary  with a content of humus 4.60%, a eaction of the soil medium (pH 6.8), the average nitrogen supply with nitrification capacity, high - mobile phosphates and high - exchangeable potassium by Chirikov.  The soil was determined: nitrogen content was determined potentiometrically using ion-selective electrode, ammonium nitrogen, photometrically using Nessler's reagent, the content of mobile phosphorus and potassium compounds in a single extraction using the Chirikov method, followed by the determination of phosphorus photometrically by the Denizhe method, and potassium on a flame photometer.  Results of the research and their discussion. Data on nitrogen content of nitrates in chernozem ordinary indicate that soil tillage is minimized by differentiating between 0 and 30 sm of the layer by the amount of nitrates with an increase in the layer of 0-10 sm and a decrease of 10-20 and 20-30 sm layer. An increase in nitrates in a layer of 0.10 sm in relation to a layer of 10-20 sm was 28.3% for minimal cultivation and 42.3% for zero cultivation; relative to the 20-30 sm layer - respectively 46.5 and 92.2%. Traditional technology with field plowing led to an inverse differentiation of the content of nitrates in the soil layers with an increase in the lower layers of a 0 to 10 sm layer.   On average, 0-30 sm layer was reduction of nitrate nitrogen content by 6% for minimum cultivation and 14.5% for zero cultivation compared to plowing. 
The content of ammonia absorbed in the 0- 30 sm layer was the highest in the version with minimal cultivation, which were created better conditions for the accumulation of ammonia nitrogen than the orang these and zero tillage in th. The advantage of minimum cultivation relative to plowing was 5.4%, in relation to direct seeding technology - 10.6%.  The changes in the distribution of ammonium nitrogen, similar to the content of nitrates, have been noted, which can be explained by a change in the biological activity in the soil layers under different soil tillage systems. The presence of ammonia nitrogen is determined by the course of microbiological processes, which depends mainly on temperature, humidity, the presence of energy material. In technology based on a plow, ammonia nitrogen in large quantities accumulates in the lower horizons.  In the layer of soil 0 - 10 sm the predominance of ammonium nitrogen content on soil protection technology was 84.5%, on direct seeding - 57.8% relative to the traditional one. In the 10- 20 sm layer of soil ammonium content absorbed almost no different options for me. The reverse dependence is noted in the lower 20-30 sm layer: the advantages of plowing were 56% in relation to the minimum cultivation and 72.3% to zero.  Some deterioration of the nitrogen regime of the soil due to the inhibition of nitrification is associated with the slowdown of the processes of organic decomposition, some decrease in the aeration of the soil and the change in microbiological activity.  Table 1 presents the results of determining the content of mobile compounds of phosphorus and potassium. For minimal cultivation, there is not only differentiation of the arable layer of soil, but also an increase in the content of phosphates. In this variant, in the 0-30 sm soil layer, the content of mobile phosphates was higher by 10 mg / kg (9.8%) when growing barley compared to plowing. In our opinion, the decrease of the content of mobile phosphates in the version of the zero cultivation is due to the large pesticidal load, which leads to the suppression of the microbiological activity of the soil. 
 The cultivation technologies influenced the nature of the redistribution of exchangeable potassium in a soil layer of 0-30 sm . In the 0-10 sm layer of black earth, the usual highest content of exchangeable potassium was zero cultivation , which is 6 % more than the minimum cultivation and 24 % relative to plowing . This is due to the nature of the receipt of plant residues and mineral fertilizers in the soil, as well as the intensity of microbiological processes. For a minimum cultivation, an increase of 0-10 sm in the layer relative to plowing was 17 %. However, 10-20 and 20- 30 sm layer of exchangeable potassium content for zero tillage is significantly lower than other options along. Minimal and zero cultivation resulted in an increase in the content of exchangeable potassium in the 0-30 sm layer by 4.2% compared to the plow .  Conclusions. 1 Minimization of cultivation of soil in leads to an increase in the content of nitrate nitrogen in a layer of soil 0-10 sm and reduce its amount in the lower layers and in general 0-30 sm layer compared to plowing. The content of ammonia nitrogen depended little on the methods of cultivating the soil in the growth of barley.  2. Minimal and zero cultivation contributed to the increase in the content of the content of mobile phosphates and exchangeable potassium.