Post-harvest Residues Research Articles

Ash Melting Behavior of Rice Straw and Calcium Additives

Rice straw is potentially an appropriate feedstock material for biofuel production, since a huge amount of this postharvest residue is generated every year. The transformation of such agricultural biomass into densified products with a higher energy value and their subsequent combustion is associated with several questions. One of them is that rice straw exhibits a large formation of ash during combustion; thus, it is essential to know the nature of its ash melting behavior. Generally, during the combustion of straw biomass, ash sintering occurs in relatively low temperatures, resulting in the damaging of heating equipment. This negative aspect can be overcome by the addition of calcium-based additives. This paper aimed to study the ash melting behavior at a laboratory scale and to determine the ash melting points of rice straw mixed with calcium carbonate (CaCO3) and calcium hydroxide (Ca(OH)2) in different proportional ratios. The standardly produced ash samples from the rice straw obtained from Cambodia were constantly heated up in a muffle furnace, and characteristic temperatures of ash melting, i.e., shrinkage, deformation, hemisphere, and flow temperature, were recorded. The results showed that increasing the additive ratio did not bring linear growth of the melting temperatures. The addition of 1% CaCO3 showed an optimal positive impact of higher ash melting temperatures, and thus a better ability to abate the sintering of the rice straw ash.

Dimethoate insecticide application seldom reduces silvertop incidence in grass seed fields on the Canadian prairies

Many arthropods have been reported (but none confirmed) as causal agents of sterile seed heads in perennial grass seed fields, known as silvertop or white head. Field studies to identify the arthropods that cause silvertop were conducted in five perennial grass species at seven sites in Saskatchewan, Canada, over several years. The effect timing of insecticide application in spring — early, mid, or late — and of post-harvest residue management — mowing, close mowing with straw removed (scalping), and burning — on subsequent arthropod populations, silvertop incidence, and seed yield were assessed. Samples of grass tillers and sweep net collections were taken regularly, and the arthropods collected were identified to family level and counted. Arthropod populations from sweep samples varied among sites and dates in number and taxon composition, but no arthropod assemblage was consistently associated with silvertop in any grass species. Thrips were the most numerous arthropods on tillers at all sites. Insecticide application often temporarily reduced arthropod populations, but reduced silvertop incidence at only 1 of 15 site-years, and increased seed yield at only 1 of 17 site-years. Scalping or burning did not reduce silvertop incidence but often increased healthy seed head numbers and seed yield relative to mowing, the standard treatment. The majority of Kentucky bluegrass fields had extremely low seed yields unrelated to silvertop or arthropod levels. This extensive study, across a range of grass species and management regimes, provides strong support for the conclusion based on previous work that arthropod pests are not the sole cause of silvertop.

Chili post-harvest residue-derived nanocellulose composite as a matrix for in vitro cell culture and Hemigraphis colorata blended nanocellulose extends antimicrobial potential

Nanocellulose is becoming a wonderful biomaterial with wider applications in food, biomedical, cosmetics, and other sectors. Nanocellulose is easily degradable, bio-derived and can be effectively used for constructing novel bioplastics which finds applications in food packaging and wound dressing. Nanocellulose was isolated from Chili post-harvest residue and its properties were evaluated using FESEM, XRD and FTIR. Cytotoxicity and viability of cells are critical characteristics defining a material for biomedical applications and these properties were investigated for Chili post-harvest residue derived nanocelluose. The cell viability of HEK293 cells was assessed and the results demonstrated that the cell viability was normal, with no cytotoxicity and DNA damaging effects. Next we examined the antimicrobial potential of NC films after blending with Hemigraphis colorata extract. The nanocellulose blended with Hemigraphis colorata extract provided effective antimicrobial activity by inhibiting the growth of Bacillus cereus, E. coli, Pseudomonas sp. and Saccharomyces cerevisiae. The antimicrobial property of NC composite suggests its potential for use in food packaging and in wound dressing material.

Influence of stubble biodestructor on soil microbiological activity and grain yield of winter wheat (Triticum aestivum L.)

The aim of the work was to improve soil fertility and increase the yield of winter wheat using the stubble biodestructor by activating the microbiological activity of the soil. The experimental studies were on the research field of Mykolayiv National Agrarian University (Ukraine). After harvesting the precursor cultures of spring barley and peas the post-harvest residues of these crops were treated with a stubble biodestructor. After treatment of crop residues of spring barley and pea by the stubble biodestructor in the soil layer of 0 up to 20 cm the quantity of cellulose-destructive microorganisms increased by 27.9·105 up to 36.0·105 cfu/g of soil depending on the predecessor culture and the degree of degradation of these residues increased by 31.4 up to 45.1%. The number of nitrogen fixators in the 0-10 cm soil layer grew under the action of treatment of crop residues of spring barley and peas by stubble biodestructor on 13.4 up to 14.1 ·106 cfu/g of soilor 30.3 up to 35.0%. At the same time, a somewhat large number of bacteria in the soil was determined by the processing of post-harvest residues of peas, which was due to the biological characteristics of this legume culture. The average for years of researches at cultivating of winter wheat after spring barley using the stubble biodestructor the grain yield increased by 0.45 t ha–1, or 20.9%, and after pea it increased by 0.67 t ha–1 or 18.8% compared to the treatment variant of stubble just with water.

Dependence of the content of microbial biomass in typical black soil on agrogenic factors and year season

The authors of the paper found that the nature and direction of the seasonal dynamics of the content of microbial biomass in typical black soil in grain-fallow crop rotation differ depending on the slope direction, the cultivation system and the soil layer. The characteristics of the dynamics of the content of microbial biomass in typical black soil in the agroecosystem of grain-fallow crop rotation, depending on the slope direction and the type of soil cultivation are revealed. The influence of the slope direction on the dynamics of the microbial biomass in the soil is more pronounced in the layer of 10-20 cm. The need to ensure the supply of a sufficient amount of post-harvest residues and organic fertilizers to the soil is shown. The increase in the uniformity of the upper layer of typical black soil is associated with the constant mechanical man-made impact on it. The obtained results about the nature of the impact of the studied factors on the seasonal and spatial variability of microbial biomass can be used in the development of systems for the management of the biological activity and reproduction of organic matter in black soils in order to improve their ecological state. The results of studies of the ecologically and agronomically important soil component i.e. microbial biomass are necessary for the development of systems for the regulation of soil fertility in order to increase their productivity, as well as for the development of a control system for the content of microbial biomass in black soils. The experimental data can serve as the basis for a database on the microbial pool of various soils and ecosystems, which is advisable to use for model predictive calculations, including in different ecological scenarios. The assessment of the state of organisms living in the soil and their biodiversity are important in the solution of the problems of environmental practice: identification of zones of ecological disadvantage, calculation of damage caused by man-made activities, determination of the stability of the ecosystem and the impact of certain anthropogenic factors.

Productivity of Short-Rotary Crop Cultivation under Different Systems of Basic Tillage in Organic Agriculture of the Steppe of Ukraine

Long-term reform of the agricultural sector in Ukraine is taking place under difficult economic and natural conditions. In modern agriculture, the most relevant ones are biologized measures and technologies for growing crops and resource- and energy-economic restoration of soil fertility. Studies of the impact of the system of basic tillage and the use of straw bio-decomposers and postharvest residues in organic farming were conducted in the most common and typical for the southern region of the steppe of Ukraine short- rotation crop cultivation with the following alternation of crops: peas – winter wheat – winter barley – ½ sunflower fields + ½ corn fields. During the years of the first cultivation, the experiment showed the advantages of a system of differentiated tillage, where even without the use of bio-decomposers, the highest yield of cereals was obtained – 3.64 tons/ha and sunflower – 2.20 tons/ha (check experiment). The application of the planar-free system combined with multi-depth and especially planar-free shallow soil processing, main tillage caused a decrease in grain yields by 0.11-0.39 tons/ha and sunflower by 0.28-0.42 tons/ha, respectively. With the use of bio-decomposers provided by brands Ecostern and Cellulad, yields’ growth is in the range of 0.13-0.25 t/ha or 4.5-8.7% for cereals and 0.10-0.23 t/ha or 5.4-12.4% for sunflower. The application of the Ecostern bio-decomposer 1.5 l/ha provided an increase in the yield from 1 ha of crop rotation area of grain, fodder, fodder-protein units and digestible protein on average in all systems of basic tillage by 4.7, respectively; 4.5; 4.3 and 5.4%, and with the introduction of Cellulad 2.0 l/ha, these figures increased by 9.5, respectively; 8.9; 8.6 and 10.8% compared to options without the introduction of bio-decomposers

Do New-Generation Recycled Phosphorus Fertilizers Increase the Content of Potentially Toxic Elements in Soil and Plants?

Phosphorus (P)-rich secondary raw materials can provide a valuable base for modern mineral fertilizers, provided that the new formulations do not load the soil–plant system with potentially toxic elements. Fertilizers from sewage sludge ash (SSA) and/or animal bones, activated by phosphorus-solubilizing bacteria (Bacillus megaterium or Acidithiobacillus ferrooxidans), were tested in field experiments in north-eastern Poland. The reference provided treatments with superphosphate and treatment without phosphorus fertilization. In one experiment, all P-fertilizers were applied at a P dose of 21 kg·ha−1, and in the other three experiments, three P doses were adopted: 17.6, 26.4, and 35.2 kg·ha−1. The effect of recycled fertilizers on the content of arsenic (As), chromium (Cr), nickel (Ni), copper (Cu), and zinc (Zn) in the soil, in wheat grain and straw (test plant), weeds, and post-harvest residues was investigated. The application of recycled fertilizers in P amounts up to 35.2 kg·ha−1 did not change the As, Cr, Ni, Cu, or Zn contents in the soil and plant biomass. The contents of these elements in soil were below the permissible levels for arable land in Poland. Their concentrations in wheat grain and straw did not exceed the permissible or suggested limits for plant material to be used for food and feed, while in the weed and post-harvest residue biomass, they usually fell within the biological plant variability ranges.

The Cumulative Effect of Various Tillage Systems and Stubble Management on the Biological and Chemical Properties of Soil in Winter Wheat Monoculture

Agricultural practices, including tillage systems and postharvest residue management, strongly affect a wide range of soil properties. Depending on the degree of soil inversion, both negative and beneficial changes of its structure, chemical composition, and biological activity may occur as a result of these treatments. The three-year experiment was carried out on the soil under winter wheat (cv. Arktis) monoculture. The effect of various tillage systems and stubble management on the soil environment’s biological and chemical features was investigated. The total number of microorganisms (TNM); bacteria (B); actinobacteria(A); fungi (F); soil respiratory activity (SR); pH in 1 M KCl (pH); organic carbon content (OC); content of available phosphorus (Pa); potassium (Ka); magnesium (Mg); and content of total nitrogen (TN) and mineral nitrogen forms were determined in soil samples. It was shown that manure application was the factor with the greatest influence on soil properties. The manure fertilization resulted in a higher number of microorganisms in arable soil. Conventional tillage procedures combined with manure application increased the amounts of available forms of phosphorus, potassium, magnesium, and mineral nitrogen. Introduction of the chopped straw in the field enhanced the beneficial effect of manure on soil properties.

Catch Crops: A Nutrient Reservoir in Post-Harvest Residues under Water Deficit

Undersowing catch crops (CCs) in cereals provides many environmental benefits and potentially contributes to building agricultural resilience to climate change. The increasing soil water deficit due to global warming is becoming a challenge for the sustainability of Central European agriculture. Some of the multiple functions of CCs may be altered under water shortage. Two pot experiments were conducted in Poland to assess the effect of water deficit on N, P, K, and Mg accumulated in post-harvest residues left by spring barley undersown with Italian ryegrass or red clover, and in the soil under these crops. In both experiments, barley grown alone provided a reference, and two levels of water supply were adopted: higher (sufficient for barley) and lower (reduced by 50%). Under water deficit, CCs undersown in spring barley maintained their function of capturing and storing nutrients. Post-harvest residues of barley undersown with CC and stressed with water shortage accumulated the same or higher amounts of N, P, K, and Mg than residues of barley grown alone under sufficient water supply. Soil nutrient contents were negatively correlated with crop biomass. Further research with other CC species and studies based on field experiments under rainout shelters are recommended.

The impact of various sowing applications on the nutritional value of Quinoa Dry Herb

The present study aimed to determine the availability of the quinoa plant residues, which are mostly grown as grain crops as fodder and the impact of various cultivation applications on nutritional value. For this purpose, the calcium, dry matter, potassium, magnesium, phosphorus, protein content, tetany, and milk fever incidences of the post-harvest residues of the quinoa plant, cultivated in different sowing times and with various row spacing applications, were investigated. Thus, it was determined that the calcium, dry matter, potassium, magnesium, phosphorus, protein content, tetany, and milk fever incidences content in quinoa straw were 0.93%–3.33%; 91.08%–87.94%; 0.73%–2.24%; 0.20%–1.24%; 0.22%–0.30%; 4.40%–7.37%; 0.17–2.67 meq, and 3.35–12.27 meq. The study findings demonstrated that the quinoa straw mineral content and balance were suitable for use as an alternative fodder source. However, due to the high milk fever incidence, it was concluded that mono and intensive use of quinoa straw may be risky. Novelty Impact Statement Quinoa straw was determined that all properties except protein content were significantly affected by the sowing time, and the row spacing led to a difference only in P content. It was concluded that the quinoa plant had rich mineral content and plant residues could be used as fodder. However, based on the mineral balance, it was concluded that the milk fever incidence was quite high when the ideal range was considered, this plant should not be given alone and intensively, and the quality of the could be improved when mixed with other feed material. Thus, it was suggested that the residues of the grain production in the quinoa plant could be an alternative fodder source to other forage plants.

Use of faba bean (Vicia faba L.) hulls as substrate for Pleurotus ostreatus – Potential for combined mushroom and feed production

A circular concept involving use of faba bean hulls for production of oyster mushrooms (Pleurotus ostreatus (Jacq.) P. Kumm.) and the post-harvest residues for feed purposes was evaluated. Faba bean hulls are a waste remaining after the beans are dehulled to decrease the content of anti-nutritional factors and increase the food value of the beans. Faba bean hulls proved very suitable as substrate for production of oyster mushrooms, with biological efficiency of 109 ± 28%. The fruiting bodies produced were comparable to commercially sold mushrooms in terms of morphology, protein content, protein quality, and chemical composition. After mushroom harvest, 48.4 ± 0.6% of initial dry weight (dwt) of the substrate remained and showed significant changes in proximate composition, with an increase in protein concentration from 207.9 ± 8.6 to 346.6 ± 16.5 g kg−1 dwt and a significant increase in 14 of 16 amino acids analyzed, including methionine. Concentrations of the anti-nutritional compounds vicine and convicine were below the detection limit after mushroom harvest, while their initial concentration was 5.7 ± 0.1 and 1.4 ± 0.04 g kg−1 dwt, respectively. Tannin concentration was reduced by approximately 50%, to a final level of 9.0 ± 1.6 g kg−1 dwt. Comparison of the spent mushroom substrate with a commonly used feedstuff for pigs indicated potential for the spent substrate to be a valuable protein source in pig diets. This study demonstrates the potential for achieving complete circular use of agro waste and has implications for development of production systems well suited in the biobased society.

ЕНЕРГЕТИЧНА ЕФЕКТИВНІСТЬ ТЕХНОЛОГІЇ ВИРОЩУВАННЯ СІЛЬСЬКОГОСПОДАРСЬКИХ КУЛЬТУР НА ЗРОШУВАНИХ ЗЕМЛЯХ ПІВДНЯ УКРАЇНИ

The article reflects the results of research on the study of crop rotation productivity and energy efficiency components of crop rotation technology in terms of depending on different methods and depth of basic tillage. The purpose of the research was to determine the impact of basic tillage and fertilization on crop rotation productivity indicators and indicators of economic efficiency of crop rotation technology in irrigated conditions in the south of Ukraine. Methods: the field, in-gravimetric, visual, laboratory, calculation-comparative, mathematically-statistical and confessedly in Ukraine methods and methodical recommendations. The research was conducted during 2016-2019 in the research fields of the Askanian SARS IIA NAAS of Ukraine. Results. The use of differentiated and shallow single-depth system of basic tillage to the same productivity indicators at the level of 8.21 and 8.22 t.o.o./ha of products. However, the use of shallow tillage with different depths increased the productivity to 8.49 tons of water/ha, or 3.3%, and with no-till the lowest productivity was obtained 7.15 tons of water/ha. At the same time, the organo-mineral system of fertilizer N90P40 + green manure + crop residues yielded at the level of 7.61 tons per hectare. The improvement of nitrogen nutrition of crop rotations to N105P40 + green manure to get her with the earning of crop residues increased this figure to 8.06 ton so.o./ha, or 5.9% more than the control. At the same time, the maximum productivity indicators of 8.52 tons per hectare were obtained for the N120P40 system + green manure + post-harvest residues, which is actually 12% more than in the control. The reduction of total energy consumption was obtained with a shallow single-depth system of main cultivation of 26.45 GJ/ha, and the lowest values of 25.27 GJ/ha were obtained with no-till, which is 6.8% less than in the control. Application of organo-mineral fertilizer system N90P40 + green manure + post harvest residues formed costs at the level of 24.94 GJ/ha, increase of nitrogen nutrition of crop rotations to N105P40 + green manure with post harvest residues increased costs to 26.35 GJ/ha, and the highest costs 26.37 GJ/ha was obtained in the variant N120P40 + green manure, where the figures were higher by 11.5% compared to the control. Almost the same energy yield was obtained for differentiated and single-depth shallow tillage systems 127.33 and 127.64 GJha, respectively. The application of the system of multi-depth tillage increased the yield to 133.24 GJ/ha. Conclusion. The calculation of energy efficiency testifies that growing of agricultural cultures at bringing of N120Р40 + green manure + post-harvest residues in the system of the plowless on different depth is most expedient and justified from the power point of view. Technology of growing, which is based on these agrotechnology measures provides the receipt of maximal energy coefficient at the level of 4,96

Availability and Applicability of Wood and Crop Residues for the Production of Wood Composites

Due to high levels of volatility in both the agricultural and the forestry commodity markets, specifically, of timber and agricultural crops, it is important to identify the risks associated with the stability of supplies necessary for the production of composite materials in the Czech Republic. This study aims to accurately estimate the availability of selected raw materials that contain lignocellulose over the next 20 years. In addition, their suitability for the production of composite materials is assessed based on their physical properties. Furthermore, in the event of scarcity involving timber in the European Union, recycled wood and post-harvest residues could replace conventional raw materials in wood-based composites such as particleboards and chipboards. The viable potential of Czech forests is predicted to be between 740 and 750 million cubic meters of timber. For agricultural crops, it is estimated at 0.9 million hectares of wheat and 0.5 million hectares of canola under the current EU biofuel policy and at 0.4 million hectares if this policy is removed. According to moisture and fibre analyses carried out in our study, the most suitable candidate for wood-based composites production is soft wood.

Changes in soil water retention following biochar amendment

ABSTRACT To mitigate water runoff from arable land, a variety of measures can be applied. One of them is the amendment of highly porous biochar to increase the water retention capacity of soils and store the runoff water. Various types of biochar are made under variable production conditions and amended to soils of different quality in a wide range of quantities. Since reported data show ambiguities due to various feedstock, pyrolysis parameters, soil characteristics, and a highly variable change in water retention capacity (WRC), robust statistical methods were applied to compare the reported data from previous studies. The results revealed that biochar increased WRC by 0.26% t ha−1 of biochar added on average. In terms of WRC, biochar produced at lower pyrolysis temperatures functioned surprisingly better than that produced at higher temperatures, which was confirmed by a decision tree made by J48 algorithm. The increase of WRC was higher with sandy soils, whereas silty and loamy soils did not show a significant increase. Biochar made from easily biodegradable, post-harvest residues such as straw or rice husk showed higher impact than others made from wood that is appreciated for its high porosity. This is a groundbreaking argument for stopping the usage of biochar for energy purposes. The high organic content in soils was the major driver damping the WRC increase. The most effective measure for increasing WRC is the application of 90 t ha−1 biochar, preferably made of an easily biodegradable phytomass that is pyrolyzed at low temperatures. The presented study compares 166 specific combinations of various biochar and soil properties, shows the effectivity of biochar amendments for WTR increment, and reviews the impact of biochar amendment in terms of water retention in agricultural landscapes.

The Soil Organic Matter in Connection with Soil Properties and Soil Inputs

The content of organic matter in the soil, its labile (hot water extractable carbon–HWEC) and stable (soil organic carbon–SOC) form is a fundamental factor affecting soil productivity and health. The current research in soil organic matter (SOM) is focused on individual fragmented approaches and comprehensive evaluation of HWEC and SOC changes. The present state of the soil together with soil’s management practices are usually monitoring today but there has not been any common model for both that has been published. Our approach should help to assess the changes in HWEC and SOC content depending on the physico-chemical properties and soil´s management practices (e.g., digestate application, livestock and mineral fertilisers, post-harvest residues, etc.). The one- and multidimensional linear regressions were used. Data were obtained from the various soil´s climatic conditions (68 localities) of the Czech Republic. The Czech farms in operating conditions were observed during the period 2008–2018. The obtained results of ll monitored experimental sites showed increasing in the SOC content, while the HWEC content has decreased. Furthermore, a decline in pH and soil´s saturation was documented by regression modelling. Mainly digestate application was responsible for this negative consequence across all soils in studied climatic regions. The multivariate linear regression models (MLR) also showed that HWEC content is significantly affected by natural soil fertility (soil type), phosphorus content (−30%), digestate application (+29%), saturation of the soil sorption complex (SEBCT, 21%) and the dose of total nitrogen (N) applied into the soil (−20%). Here we report that the labile forms (HWEC) are affected by the application of digestate (15%), the soil saturation (37%), the application of mineral potassium (−7%), soil pH (−14%) and the overall condition of the soil (−27%). The stable components (SOM) are affected by the content of HWEC (17%), soil texture 0.01–0.001mm (10%), and input of organic matter and nutrients from animal production (10%). Results also showed that the mineral fertilization has a negative effect (−14%), together with the soil depth (−11%), and the soil texture 0.25–2 mm (−21%) on SOM. Using modern statistical procedures (MRLs) it was confirmed that SOM plays an important role in maintaining resp. improving soil physical, biochemical and biological properties, which is particularly important to ensure the productivity of agroecosystems (soil quality and health) and to future food security.

Nitrogen Uptake from Different Sources by Soybean Grown at Different Sowing Densities

The objective of the research reported here was to determine the amount of nitrogen fixed from the atmosphere and taken up from mineral fertilizer and soil reserves by soybean cv. Abelina grown at three densities (per 1 m2) under central European conditions. Moreover, an attempt was made to determine what amount of nitrogen taken up from the individual sources was removed from the field with seed yield and was introduced to the soil with post-harvest residues and that will be the source of this macronutrient for the following plants. The following densities were used: A1–50 seeds, A2—70 seeds and A3—90 seeds per 1 m2. The share of nitrogen derived from the atmosphere, soil reserves and mineral fertilizer and taken up by the total plant biomass was 46.28, 45.52 and 8.2%, respectively. The whole biomass accumulated 58.51, 52.85 and 9.71 kg N∙ha−1 from the respective sources. An average of 95.24 kg N∙ha−1 was removed from the field with seeds, it being 46.17, 42.20 and 6.68 kg N∙ha−1 for an uptake from the atmosphere, soil reserves and mineral fertilizer, respectively. An incorporation into soil of residues and roots provided over 25.82 kg N∙kg−1 associated with all the sources.

Sources of Nitrogen for Winter Triticale (Triticosecale Wittm. ex A.Camus) Succeeding Pea (Pisum sativum L.)

Atmospheric nitrogen biologically reduced in legumes root nodule and accumulated in their postharvest residues may be of great importance as a source of this macronutrient for succeeding crops. The aim of the study was to determine nitrogen uptake by winter triticale from pea postharvest residues, including N fixed from atmosphere, using in the study fertilizer enriched with the 15N isotope. Triticale was grown without nitrogen fertilization at sites where the forecrops had been two pea cultivars (multi-purpose and field pea) and, for comparison, spring barley. The triticale crop succeeding pea took up more nitrogen from the soil (59.1%) and less from the residues of the forecrop (41.1%). The corresponding values where the forecrop was barley were 92.1% and 7.9%. In the triticale, the percentage of nitrogen derived from the atmosphere, introduced into the soil with pea crop residues amounted to 23.8%. The amounts of nitrogen derived from all sources in the entire biomass of triticale plants grown after harvesting of pea were similar for both pea cultivars. The cereal took up more nitrogen from all sources, when the soil on which the experiment was conducted had higher content of carbon and nitrogen and a greater amount of N was introduced with the pea residues. Nitrogen from pea residues had high availability for winter triticale as a succeeding crop cultivated on sandy soils.

Продуктивність просапної сівозміни за мінімізованого і нульового обробітків ґрунту в умовах зрошення півдня України

Goal. To determine the productivity of 4-field crop rotation with minimized and zero main tillage and organomineral fertilizer systems using post-harvest residues and green manures in the conditions of irrigation of the South of Ukraine. Methods. Field, quantitative, visual, laboratory, computational, mathematical, and statistical methods using generally accepted in Ukraine methods and guidelines. Results. The data are given of experimental researches of formation of productivity of cultures of 4-field row crop rotation at various basic cultivation of soil and fertilizers on the irrigated lands in a zone of action of the Kakhovka irrigation system. It was found that the highest productivity was provided by crop rotation on the background of different depth chisel main tillage, which under the organomineral fertilizer system using after-harvest residues and green manure on the background of different doses of mineral fertilizers provided 8.06–9.10 t/ha of grain units. The use of green manure for fertilizer helped to increase crop rotation productivity with differentiated and shallow (12–14 cm) single-depth disc loosening by 6.5%, with different depth chisel — by 7.4, for zero — by 9.2%. Conclusions. On dark chestnut soil in the conditions of irrigation of the South of Ukraine, the highest productivity was provided by row crop rotation with different depths of shelfless main cultivation on the background of organomineral fertilizer system with N120P40 application and use for fertilizing of by-products of crop rotation and green manure.

Productivity of soybean varieties under different irrigation regimes

Abstract. World soybean acreage increases by 3 million hectares annually with average yield of 2.7 t/ha. Significant growth of soybean production in Russia is constrained by increased climate aridization and a declining yield of up to 1.5 t/ha. An important factor in intensification of soybean production is to expand its crops under irrigation. Introduction of adapted and high-yielding varieties of regional selection, followed by improvement of crop water supply, increases yields up to 34 t/ha. Soybean varieties selected by Russian Research Institute of Irrigated Agriculture and admitted to production in the Lower Volga region: VNIIOZ 86 (since 2002), VNIIOZ 31 (since 2011), Volgogradka 2 (since 2020) were studied. The experiments were conducted at Russian Research Institute of Irrigated Agriculture in 2013-2015. The experiment included two factors: factor A - varieties, factor B - irrigation regime (70-80-70 % of FMC, 80-80-70 % of FMC and control - 80-80-80 % of FMC). Plots of the 1st (600 m2) and 2nd (200 m2) order were sown in 4-fold replication by a wide-row method (0.7 m) in mid-May with a planned yield of 2.53.5 t/ha (N90P90K60 a. i./ha). Soybean varieties differed in peculiarities of crop structure formation. Differentiated irrigation regime resulted in more cost-efficient water consumption followed by yield increase compared to the control. The highest yields were formed by Volgogradka 2 variety (2.873.23 t/ha) and VNIIOZ 31 (2.823.19 t/ha), which was significantly higher than in VNIIOZ 86 variety (2.172.51 t/ha). The variable irrigation regime led to yield increase in all soybean varieties, especially in Volgogradka 2 - by 0.310.36 t/ha (10.812.5 %) as compared to the control. It was due to grain increase to 30.936.2 % in the total biomass compared to the control values - 26.627.5 %. The highest amount of post-harvest plant residues (stems, leaves and roots) remained after harvesting Volgogradka 2 (6.397.63 t/ha) and VNIIOZ 31(6.737.9 t/ha), which improved soil fertility well, and the smallest amount was after VNIIOZ 86 variety (4.415.66 t/ha). Differentiated irrigation regime led to decrease in vegetative mass in soil - 4.417.42 t/ha compared to the control (5.667.9 t/ha). Thus, Volgogradka 2 and VNIIOZ 31 can be recommended for irrigated agriculture in the Lower Volga region, as they provide high yields under differentiated (relatively cost-efficient) irrigation regime and improve soil fertility due to large biomass remained in soil after harvesting.

Influence of methods of basic tillage on the dynamics of productive moisture reserves in spring barley crops in the conditions of the northern Steppe of Ukraine

The yield of spring barley significantly depends on the reserves of soil moisture, which ensures the implementation of all important life processes, including seed germination and rooting of seedlings, transpiration, thermoregulation and supply of nutrients to the plant. The productivity of spring barley is directly proportional to its moisture content. With sufficient soil moisture, favorable conditions for the growth and development of field crops, and ultimately increases their yield. In the northern steppe, high productivity of spring barley, provided timely and full germination, is formed due to moisture reserves accumulated in the deep layers of the soil during the autumn-winter period of the year. The purpose of the study was to study the influence of the methods of basic tillage on the accumulation and dynamics of soil moisture in spring barley crops and the level of its yield. Experimental studies were performed during 2004–2015 in a stationary field experiment at the Institute of Grain Crops of the National Academy of Sciences of Ukraine. The presence of wavy nanorelief during chiselling, as well as plant remains on the ridges contributed to a significant reduction in wind speed in the aboveground layer. Snowfall was concentrated in the depressions and was reliably protected from blowing. Due to this, the height of the snow cover here, according to our data, was the highest and amounted to – 14.3 cm, and as a result faster thawing of the soil and better accumulation of water. At the same time, the intensity of wet accumulation during the autumn-winter period when treated with chisel tools outweighed the options of shelf plowing by an average of 17.9 mm, and disking – 9.2 mm. The increased assimilation of cold precipitation during chiselling can also be associated with strip loosening of the soil in the furrows, which is typical for chisel units. It is established that in the northern steppe the use of canning (chisel) with a differentiated tillage system for spring barley increases the accumulation of moisture by 91.0–179.0 m2/ha in the autumn-winter period due to plant residues that retain more snow, especially in warm snowless winters. It is proved that the use of a fine mulching system of tillage, despite the reduction of grain yield, contributes to a more economical consumption of moisture per unit of crop in 1.1–1.2 times when growing spring barley. It was found that the use of annual shelf and differentiated tillage on average over the years of research provides the maximum level of yield, and the minimization of tillage in most years led to its reduction by 0.22–0.55 t/ha. The use of chiseling in a differentiated tillage system is most effective in dry years and even outweighs plowing due to the greater accumulation of productive moisture due to the presence of a significant portion of post-harvest residues of the predecessor that retain moisture under the mulch. Key words: spring barley, tillage, soil moisture, fertilizers, disking, yield.