Soil Application of Zeolite Affects Inorganic Nitrogen, Water Soluble and Exchangeable Potassium

An incubation study was conducted at college of agriculture, rajendranagar, PJTSAU to evaluate the influence of zeolite application on inorganic nitrogen, water soluble and exchangeable potassium in soil. Clinoptilolite Zeolite was fully mixed with soil (7.5 t ha-1) at the start of the experiment. Nitrogen was applied to soil through urea (200 kg ha-l). The experiment was conducted for 35 days and soil was analyzed for inorganic nitrogen, water soluble and exchangeable potassium at weekly intervals i.e., 1, 7, 14, 21, 28, 35 days of incubation. The results indicated that the treatment with zeolite application showed significantly higher ammoniacal nitrogen from day 1 (136.54 mg kg-l) to day 35 (38.71 mg kg-l) as well as nitrate nitrogen (day 1 – 59.13 mg kg-l; day 35 – 130.13 mg kg-l). Similarly water soluble (day 1 – 92.21 kg ha-l; day 35 – 103.13 kg ha-l) and exchangeable potassium (day 1 – 363.69 kg ha-l; day 35 – 393.94 kg ha-l) was also significantly higher in zeolite applied treatments. Thus, mixing of zeolite into soil improves inorganic nitrogen through reducing leaching losses and also improves water soluble and exchangeable potassium.

Potassium status of sod-podzolic loamy soils

Potassium is one of the essential plant nutrients. Despite numerous surveys, some issues related to the transformation of potassium in soils require additional study. The purpose of the research was to study the potassium transformation in sod-podzolic loamy soils and its entry into plants influenced by various farming methods in long-term field experiments of different duration. Field experiments were conducted at the experimental station of the FSBSI “Pryanishnikov Institute of Agrochemistry” located in the Moscow region, Domodedovo district, village of Barybino. To study the potassium status, an archive of soil samples created in the Geographical Network of Experiments with Fertilizers was used. Soil samples were collected in long-term field experiments after their closure (experiment SH-8, year of laying – 1971–1973, duration – 14 years) or modification (experiment SH-5, year of laying – 1964-1966, duration – 28 years). The experimental schemes included the systematic introduction of various fertilizing systems (organic, mineral, organo-mineral) and the determination of their impact on crop rotation productivity and soil fertility. Previous studies have shown that the formation of the crop yield in the context of long-term potassium deficiency burdened by the absence of fertilization was chiefly due to the consumption of non-exchangeable potassium by plants. For the 14–year period, the annual use of non-exchangeable potassium in the control and NP variants was 62.0-63.0 kg K2O/ha. As potassium reserves in the soil of the control variant become depleted (longer experiment), its assimilation from the non-exchangeable form decreased by 1.6 times and amounted to 39.5 kg K2O/ha. The use of a mineral fertilizing system (potassium dose < 90 kg/ha for 14 years) increased the annual mobilization of the non-exchangeable form of the element (over 100 kg/ha of K2O). The transformation of soil potassium forms that differed in the degree of their availability for plants was determined by the fertilizing systems, the doses of potassium fertilizers in the systems, as well as the duration of the experiments.

The Effect of Land Management Practices on Soil Quality Indicators in Crete

The effects of four main practices tillage versus no-tillage, and intensive grazing versus extensive grazing, applied in characteristic agricultural and grazing lands of Crete Island were evaluated in situ using nine soil quality indicators. The following nine representative indicators of soil quality assessment were assessed using the rapid visual assessment methodology adopted at European level in the context of the EU research project iSQAPER: susceptibility to water and wind erosion, surface ponding (under cropping), formation of tillage pan, soil color, soil porosity, soil structure, susceptibility to slaking, infiltration rate, and biodiversity status. These indicators were measured in 48 agricultural field-plots to adequately represent the four above-mentioned practices and the different types of geomorphological patterns existing in the area. Additionally, 38 agricultural fields were sampled in the topsoil to assess cultivation practices (tillage, no-tillage) on soil organic carbon, cation exchange capacity, exchangeable potassium, available phosphorous, and soil aggregate stability. Based on the indicators rating methodology, the appropriate statistical tests were applied and the soils under different managements were characterized in terms of their potential quality and their general agricultural value. The obtained data showed that in agricultural areas, significant differences were detected between tillage and no-tillage management practices for the indicators of soil structure and consistency and infiltration rate. In grazing land, significant differences were found for the soil quality indicators of susceptibility to erosion and infiltration rate for the corresponding practices of intensive and extensive grazing. Organic carbon content, exchangeable potassium content and aggregate stability were greatly affected in tillage versus no-tillage management practices.

The content of exchangeable potassium in the soil depending on the method of tillage and meteorological factors

The article is a continuation of a series of publications on the results of the study of nutrient elements in the soil-plant system against the background of global and regional climate change, given the possibility of minimizing tillage. In the conditions of stationary field experiment on ordinary chernozem (Calcic Chernozem) in the Donetsk region for five years (1994-1998) it was monitored the content of exchangeable potassium in the arable layer of the soil under the row crop corn within the grain-growing crop rotation on the options of plowing and subsurface non-turning tillage under the same mineral fertilizer system. At the same time, the dynamics of precipitation and air and soil temperature were recorded. According to the results of research, it is a steady effect of meteorological factors on the level of potassium nutrition of plants and a general tendency to decrease the average level of exchangeable potassium contents in the soil under vegetative plants of maize within the arable layer, mainly due to layers of 10-20 cm and 20-30 cm. It is shown that for plowing the optimum of humidity of the previous year is characterized by hydrothermal coefficient of Selianinov (HTC) 1.0, and for subsurface non-turning tillage - 1.25. With a very dry (HTC 1.5), subsurface non-turning tillage may be more favorable for potassium mobility. But within the HTC 0.5-1.5 is more acceptable plowing. It is determined that the refusal to plowing leads to a decrease in the dependence of potassium mobility in the soil layer 0-30 cm on temperature, protecting from temperature fixation of potassium, and enhances the influence of the humidification regime in May. But dry and cool autumn is a likely cause of reduced potassium mobility without plowing. All conclusions are confirmed by the results of correlation, regression and variance (ANOVA) analysis.

Influence of multipurpose compost on agrochemical indicators of sod-podzolic soil and crop productivity in reclaimed agricultural landscapes

The aim of the research is to study the effect of multipurpose compost on the agrochemical indicators of sod-podzolic soil and the productivity of field crop rotation in reclaimed agricultural landscapes of the humid zone. Methodology and methods of research. The studies were carried out at an experimental area in the Tver region in 2013–2019 on a drained soddy-podzolic gley soil. Multipurpose compost was applied for sowing spring wheat at a dose of 12 t/ha, which is N300P180K120. Subsequently, the aftereffect of compost on soil properties and crop productivity in the crop rotation was studied: spring wheat – spring rapeseed (for green manure) – winter rye - oats with over-sowing of grasses – a mixture of 1–3 years of use. Grain crop rotation was deployed in time. Results. It was found that the level of mobile phosphorus increased by 7.4–23 %, exchangeable potassium – by 6.8–26.5 %. In areas with a low content of nutrients, the accumulation of mobile phosphorus (in the eluvial-transit variant of the northern slope) and exchangeable potassium (in the transit northern slope) increased by 23.6 and 26.5 %, respectively. On variants of the experiment with a high content of nutrients, their content decreased slightly over seven years. The amount of easily hydrolyzable nitrogen during the rotation of the crop rotation decreased by 13.4–57.2 %. The content of organic matter increased by 6.7–11.9 % (rel.). Soil acidity (pHKCl) during the rotation of the crop rotation increased by 0.03–0.23 units. The greatest acidification of the soil solution was noted in the transit-accumulative variant of the northern slope (by 0.23 units). It was found that the use of multipurpose compost contributed to an increase in crop yield on average per rotation by 1.6–13.2 c/ha of feed units. The maximum yield increase (44%) was obtained in the eluvial-transit and transit variants of the southern slope. Scientific novelty. The dependence of agrochemical indicators of sod-podzolic soil and crop productivity on the use of multipurpose compost in individual agromicrolandscapes has been established.

Nutrient regime of irrigated meadow-chernozem soils under long-term intensive use

The patterns of phosphorus and potassium status of soils were studied given the improvement of agricultural technologies of irrigated agriculture. Long-term studies were carried out in an experimental grain-grass crop rotation on irrigated meadow-chernozem soil. The experimental plot is located in the southern forest-steppe of Omsk region. Intensive use of irrigated arable land with a rational combination of moisture and mineral nutrition regimes contributes to obtaining maximum yields of forage and grain crops. The creation of various conditions for mineral nutrition due to an increased and high supply of mobile phosphorus and with the application of different options of agricultural technologies made it possible to simulate possible agro-ecological conditions that form contrasting indices of crop productivity. A comparative assessment of the effectiveness of various agricultural approaches to growing crops under irrigation conditions indicates that soil cultivation techniques and forecrops did not significantly affect the content of available phosphorus in the soil. The equilibrium content of mobile phosphorus given a long-term negative balance changed insignificantly. The systematic application of phosphorus-containing fertilizers significantly increased the phosphate status of the soil. However, an adequate assessment of the phosphate status of arable soils is possible using several diagnostic indices (methods). Long-term intensive use of irrigated arable land has reduced the reserves of easily exchangeable potassium from 4 to 1–2 mg/100 g of soil in the arable layer. The content of exchangeable potassium has also decreased by almost 2 times, but the soil remains in a high and very high class of its availability. However, a number of indicators show its increasing depletion in the most mobile fractions of soil potassium. The reserves of non-exchangeable potassium are more stable, which have decreased by about 19% over 40 years, and the soil has passed into the category with an unstable supply.

Forms and Dynamics of Soil Potassium in Acid Soil in the Wolaita Zone of Southern Ethiopia

Quantity-intensity characteristics are among conventional approaches for studying potassium dynamics and its availability; this was assessed to determine availability in four districts: namely, Sodo Zuria, Damot Gale, Damot Sore, and Boloso Sore at three different land use type viz., enset-coffee, crop land, and grazing land. There was water soluble, ammonium acetate, nitric acid extractable potassium, exchangeable potassium, and non-exchangeable potassium studied in soil samples, which were collected from 0-20 cm depth of each land type. The study revealed that water soluble and ammonium acetate extractable potassium concentrations ranged from 0.04 to 0.42 cmolKg-1 soils enset-coffee and grazing land use types, respectively. The study showed that exchangeable potassium constituted the highest proportion of available potassium, while the proportion of water soluble potassium was found to be the lowest. In this study, non-exchangeable potassium concentrations varied from 0.10 to 0.04cmolKg-1soils for enset-coffee, and crop and grazing land use type. Furthermore, available potassium and exchangeable potassium concentrations were positively correlated with OC(r=0.95***), cation exchange capacity, and sand and clay(r=0.98***). In addition, the K dynamics as impacted by land use types found that the highest change in exchangeable potassium (0.31cmolkg-1soils) and potential buffering capacity (1.79cmolkg-1soils) were noted in crop land use types, whereas the lowest change(1.26cmolkg-1 soils) was observed in the enset-coffee system, The varying properties, potassium status, dynamic and land use type of soils identified in the study areas provided adequate information to design soil potassium management options and further research about the soil in each site. Therefore, application of site specific soil fertility management practices and research can improve soil potassium status and quantity intensity parameters to sustain crop productive soils.

Possibility of using technogenically polluted floodplain landscapes

The article provides a modern assessment of technogenically polluted floodplain landscapes of various rivers of the Polesian Lowland. The carried out ecological monitoring of productivity, radioactivity of perennial grasses and fertility of floodplain soils revealed the following results, tendencies and regularities: the most favorable set of conditions for obtaining an air-dry mass of grasses with the highest productivity up to 5 t / ha was found on the floodplain of the Iput River, possibly used as hayfields floodplain lands at present, with a 137Cs pollution density below 555 kBq / m2 obtained after the Chernobyl accident, the use of floodplains as hayfields with a 137Cs pollution density above 555 kBq / m2 is impossible, coarse fodder from the floodplains of the Iput and Besed rivers is 6.4 and 6.6 times higher than the permissible level of 137Cs content in products, the content of organic matter, calcium and magnesium grew in the landscape of the floodplain by subsystems: near-river → central → near-terrace landscape, a high content of mobile phosphorus and exchangeable potassium, respectively, from 227 to 362 and 122 to 266 mg / kg were found in the near-terrace subsystem of the studied floodplains, the effect of fertility on an increase in productivity is positive, with the exception of the effect of acidity and negative on an increase in specific activity 137Cs, established an average role (0.30 ˂ r ˂ 0.70) of fertility indicators in increasing productivity, the correlation coefficient (r) ranged from 0.41 to 0.64 and -0.38, revealed a strong role (r ˃ 0.70) of the content of phosphorus available for a plant in a decrease in the specific activity of 137Cs in the air-dry mass of grasses, the correlation coefficient (r) was –0.70.