Natural Soil Fertility Research Articles

Evaluating the environmental and agronomic implications of bone char and biochar applications to loamy sand based on sorption data

BackgroundThe widely adopted use of charred biomass for agronomic and environmental purposes; and the reported positive and deleterious effects necessitated the need for this study to ascertain the potential causes of the erratic results surrounding the use of charred biomass in agriculture and the environment. A batch sorption experiment was carried out to determine the sorptive and desorptive capacity of bone char and biochar on nitrate, ammonium, phosphate and sulphate concentrations in a loamy sand soil. The potential agronomic and environmental implications of the sorption data were also discussed.ResultsThe results indicated that bone char is richer in nutrient composition than biochar, with 70% more ability to sorb nutrients. The bone char and biochar sorption isotherms conformed to the H-curve isotherm type. Bone char and biochar have multiple layers of adsorption sites. Nutrient adsorption maxima, binding energy, and maximum buffering capacities of the soil were increased with the addition of bone char and biochar. The unamended soil was observed to retain as low as 6% of added nitrate to as much as 58% of added phosphate, while bone char retained 56% of added sulphate, 47% of phosphate, 76% nitrate and 64% of ammonium. Generally, bone char retained 60.6% of the added nutrients, while biochar retained 40.7% of the nutrients. The addition of bone char led to a 45.8% increase in the nutrient retention ability of the soil and a 36.1% increase with the addition of biochar.ConclusionThe nutrient sorption characteristics of biochar should be studied prior to its use as a soil nutrient amendment. It was concluded that bone char or biochar is a potential soil nutrient immobilizer; hence, applications for agronomic purposes should take cognizance of the native soil fertility so as to appropriately add fertilizer input before use.

Soil fertility based on mineralogical properties to support sustainable agriculture management

<p>Detailed information on soil mineral composition has been crucial in providing the basis for designing sustainable agricultural practices, as this information offers long-term insights into natural soil fertility. This research aimed to further investigate the characteristics of soil mineral composition as a basis for managing soil fertility. Three soil profiles representing three different parent materials have been examined in the field, and soil samples have been collected for laboratory analysis. Profile 1 originates from the Raung Volcano Rock Formation (Qhvr). Profile 2 originates from the Sukamade Formation (Toms). Profile 3 originates from Puger Formation (Tmp). The presence of Mount Raung volcanic influence results in distinct soil characteristics in Profiles 2 and 3 compared to typical sedimentary and karst rock soils. The sand fraction minerals in all three profiles are predominantly composed of opaque minerals, followed by rock fragments, ferromagnesian mineral series (olivine, augite, hypersthene, and hornblende), plagioclase minerals (anorthite, biotite, and labradorite), iron concretions, epidote, and tourmaline. The clay fraction minerals in all three profiles consist of illite, kaolinite, and quartz. The minerals illite and ferromagnesian groups in all three profiles play a significant role in increasing the availability of potassium, calcium, and magnesium nutrients, thereby reducing the need for fertilizers for these elements. The soils in all three profiles naturally possess good fertility; however, designing a sustainable agricultural system requires consideration of the morphology, landform, and climate of all three profiles.</p>

Optimizing Slow-Release Fertilizer Rate for Crop and Soil Productivity in Kimchi Cabbage Cropping Systems in the Highlands of Gangwon Province

Slow-release fertilizer (SRF) improves Kimchi cabbage (KC) productivity in the Highlands of Gangwon Province in South Korea; however, optimum rates for the region are not established. This study investigated the optimum and most economical rate of SRF that maximizes KC yield, nutrient uptake and nitrogen use efficiency (NUE) and enhances soil quality in two experiments at the Highland Agriculture Research Institute. Post-harvest soil N (mg kg−1), P2O5 (mg kg−1), K, Ca and Mg (cmolc kg−1), pH (1:5), electrical conductivity (EC; dSm−1) and organic matter (OM; g kg−1) were measured to assess soil quality. Added net returns (ANR) of treatments were evaluated. Recommended N rate (238 kg ha−1) for KC production was the basis for treatment applications. Treatments included no fertilizer control (‘nf’), full N recommendation SRF (SF1), ½ N recommendation SRF (SF0.5), double N recommendation SRF (SF2) and full N recommendation conventional fast fertilizer (FF). Results showed that SF0.5, SF1 and SF2 influenced the highest KC marketable yield in both experiments (66–74 and 42–66 Mg ha−1, respectively). SRF rates between 0.5 and 1 times the N recommendation produced the highest possible linear increases in marketable yield; and the most economical, with ANR > KRW 83 million ha−1 in the first experiment and > KRW 22 million ha−1 in the second. Crop N, P, K, Ca and Mg uptakes were highest among the three SRF rates in both experiments. SF0.5 influenced the highest (91%) NUE in the first experiment; however, it left 8 mg kg−1 N by the end of this experiment compared to the start-up 27.2 mg kg−1 N. Thus, nutrient mining occurred. Soil N increased between 23 and 135 mg kg−1 by SF 1 and 2 in both experiments. Soil EC spiked to 0.6 dSm−1 from the initial level of 0.2 dSm−1 by SF2 in the first experiment. Soil pH, P2O5, K, Ca and Mg levels post-harvest were comparable among treatments in both experiments. SF0.5, 1 and 2 increased soil OM by 7–16% above pre-experimental levels in the second experiment. In conclusion, SRF rates between 0.5 and 1 for KC produced the maximum corresponding KC yield and were the most economical. SRF rates ≤ 0.5 pose risks of nutrient mining, which could jeopardise native soil fertility. SF1 and 2 improved some soil quality indices (N and OM). However, SF2 potentiates risks of soil salinity and large P losses, and it is less economical. Therefore, for holistic sustainability of the cropping system, the optimum SRF rate should lie between 0.5 and 1 N recommendation.

Coordination among leaf and fine-root traits along a strong natural soil fertility gradient

Coordination among leaf and fine-root traits along a strong natural soil fertility gradient

SCIENTIFIC SUBSTANTIATION OF THE PRODUCTIVITY OF SOWING ALFALFA DEPENDING ON SOIL AND CLIMATIC CONDITIONS OF THE FOREST-STEPPE OF UKRAINE

The article presents a review of literature sources on the study of alfalfa productivity depending on the influence of sowing dates, mineral phosphorus-potassium nutrition, soil liming, pre-sowing seed treatment with bacterial preparations and modes of grass stand use when grown for fodder purposes. It was found that the change of photoperiod in the year of sowing was a signal in alfalfa plants to pass through the microstages of growth and development, which was determined by the length of daylight hours and sowing dates, regardless of hydrothermal resources. Observations showed that the crop reached the beginning of flowering phase (code 61-62 of the BBSN) at daylight hours of 14:53-16:12 h, while at 12:48 h it reached the budding phase (code 49 of the BBSN). Regardless of climate change, which has been observed for more than a decade, sowing alfalfa provided the highest productivity indicators with early spring sowing and long-term use of the grass stand. Over the three years of vegetation, its leaf mass yield averaged 47.03 t/ha, dry matter yield was 11.09 and 2.07 t/ha of crude protein, and gross and metabolizable energy were 204.72 and 104.52 GJ/ha, respectively. At the same time, with the recommended summer sowing date (20 July), the indicators decreased by 9.1, 11.5, 13.1, 12.2 and 11.7%, respectively. Analysing the agro-ecological resources of Ukraine, given the natural soil fertility, moisture, temperature and light conditions, they are quite favourable for the maximum realisation of the biological potential of the fodder productivity of sowing alfalfa within the yield of fodder units of 10-12 t/ha and 1.8-2.2 t/ha of digestible protein. Among the elements of intensifying the cultivation of seed alfalfa for the production of plant raw materials and harvesting of various types of fodder, fertilisation is the most effective factor influencing their quantity and quality. To calculate the amount of mineral fertiliser, we take into account the biological characteristics of the crop, its cyclical growth and development during the growing season, the method of sowing and the duration of grassland use. Regardless of the geographical origin of the seed alfalfa, for two years of using the grass stand and observing technological measures of cultivation (lime, phosphorus-potassium mineral fertilisers, seed inoculation), alfalfa provided the highest yield of crude protein of 5.83-5.97 t/ha when mowing the first mowing in the flowering phase, the second - at the beginning of flowering and the third in the budding phase. Mowing of three mowings of sowing alfalfa at the beginning of the flowering phase contributes to the effective use of the light regime of the growing season as the main factor in increasing productivity. Innovative technologies for growing seed alfalfa use growth-regulating agents of various origins, microfertilisers and biological seed treatment products to increase yields and dry matter quality for foliar feeding. The complex application of these preparations provides an increase in the yield of leaf mass by 16.6-18.2%. Thus, in the context of modern agricultural development, alfalfa is one of the components of reducing the anthropogenic load on the agro-ecological system and increasing the production of environmentally friendly high-protein feed and livestock products for the purpose of efficient use of hydrothermal resources and environmental protection.

ОТ ИССУШЕНИЯ ПОЧВЫ ДО ЛИКВИДАЦИИ ГОСУДАРСТВ

The article, based on an analysis of the phenomenon of the death of civilizations (states), shows that the identified signs of this phenomenon are observed in the modern era. But if previously the signs caused by a decrease in natural soil fertility due to disruption of the cycle of four forms of organic matter in agriculture were reduced to the drying out of the soil introduced into agricultural activity and the loss of biota, then today new signs are being added to these signs. These include floods, desertifica-tion, shallowing of rivers and lakes, pollution of the environment, including seas and oceans, with human waste, which threatens humanity with famine and world war for the remaining fertile lands.

Mechanical and biological methods of plant protection against agrophages in the context of the European Green Deal strategy

The intensive development of agriculture in Europe has caused that all European Union member states are currently increasingly expe¬riencing negative consequences such as depletion of natural resources, increased erosion and loss of natural soil fertility, increased importance of new diseases and pests, water shortages, reduced biomass production and decreased biodiversity of organisms. In the context of the common agricultural policy, as well as the need to limit the use of chemical protection of agricultural crops, agrotechnical and also mechanical and biological methods are gaining in importance. Mechanical methods of protecting plants against pests main¬ly consist in mechanical destruction of threats or preventing them from reaching plants in the field or agricultural products stored in storage. Biological methods, on the other hand, use viruses, microorganisms and macroorganisms to combat pests as an alternative to chemical plant protection. This publication presents available mechanical and biological methods that allow for minimizing the use of chemicals in agriculture.

ПОЛИТЭКОНОМИЯ – ОТ «КАПИТАЛА» ДО СОВРЕМЕННОСТИ

The article shows that the economic theory of the production of utilities and their distribution in society, originating in the works of Aristotle and formed into the science of “Political Economy” in the works of Petty, Kene and Smith, through Hegel’s dialectics and Liebig’s theory of mineral fertility, became an integral part of the doctrine of human society in the works of Marx and Engels. These works indicate that “the production of food is the very first condition of life ... for producers and all production in general.” Since that time, farming in the world has been carried out according to the recommendations of the teaching of «Agrochemistry», as a modern paradigm of agriculture, the basis of which is Liebig’s theory. Justifications are given for the fallacy of this theory, and the implementation of the paradigm leads to the degradation of the natural soil fertility of the land, the growth of unproductive costs in agriculture, the weakening of states and is the main reason for the growing threat of famine and the approach of the world to war for the remaining fertile lands.

RESEARCH ON THE MANAGEMENT OF THE MAIN CHEMICAL PROPERTIES OF CHROMIC LUVISOLS FROM FARMS/HOUSEHOLDS AGRITOURISTIC IN DOLJ, IN THE PERIOD 1995-2021

The research addresses an original and complex topic concerning the evolution of the main chemical properties of the chromic luvisols in the southwestern part of Romania, in Dolj County, exploited under the specific cultivation conditions of agritourist farms. The novelty of this research consists in the multidisciplinary interpretation of the analyses on chemical properties and their influence on the quality and quantity of agricultural productions. In the second part, the main chemical properties of the chromic luvisols were analysed, both for the soil developed under woody vegetation, and both for the cultivated soils. Comparing the results of the analyses, we found that the natural fertility of the cultivated soil decreased considerably, which led to a significant deterioration of the main chemical properties, precisely due to cultivation. In the third part, a study was carried out on the presence and concentration of heavy metals in this type of soil, finding from the interpretation of the analyses that the values of all the studied elements fall below the alert threshold. he recommendation on the researched aspects is that in order to limit the degradation and even improve the main chemical properties of chromic luvisols, in the agritourism farms, an ecological agriculture must be practiced.

Agriculture: A Pathway to Create a Sustainable Economy

Agriculture has emerged as a critical sector for constructing a long-term economy that balances economic growth, social well-being, and environmental stewardship. This report examines the relationship between sustainable agricultural practices, economic development, and environmental protection in order to create a sustainable economy through agriculture. It emphasizes the critical significance of sustainable agriculture in generating economic prosperity. It explores how organic farming, agroecology, and precision agriculture improve production, maximize resource usage, and minimize input costs. These approaches not only promote agricultural output but also help to improve food security, farmer income, and rural livelihoods. It explains how sustainable agricultural techniques safeguard natural resources, soil fertility, water quality, and biodiversity. Sustainable agriculture guarantees long-term sustainability of agricultural systems by protecting the environment, mitigating the effects of climate change, and lowering the risk of environmental damage. It explores how sustainable agriculture fosters entrepreneurship, value chain development, and market connections, resulting in job creation, income production, and rural economic regeneration. It emphasizes the significance of supportive policies, financial access, and market-oriented initiatives in unlocking the economic potential of sustainable agriculture.
 
 Keywords: Sustainable Agriculture, Biodiversity, Value chain development, Agricultural ecology

Effects of Vermicompost and Inorganic Fertilizers on Growth and Yield of Sesame

A field experiment was conducted at the BINA substation farm, Ishwardi, Pabna during 2021- 2022 to see the combined effects of vermicompost and inorganic fertilizer (Urea, TSP, MoP, gypsum, zinc and boron) on sesame growth and yield. Five treatments combination were used in the experiment. The treatments were T1=Native soil fertility (No fertilizer and manure), T2=100% Chemical Fertilizers (CF), T3= Vermicompost (VC) @ 5 ton/ha, T4=50% CF + 2.5 ton/ha VC, T5=70%CF + 1.5 ton/ha VC. Yield and yield contributing characters of sesame were significantly influenced with the different treatments. The treatment T4 (50% CF + 2.5 tha-1 VC) gave the highest seed yield of sesame. The results indicated that treatment T4 enhanced more crop growth which influenced on greater seed yield of sesame. The lowest seed yield was recorded at T1 treatment. However, considering maximum yields the treatments T4 could be used for more production of sesame with less use of chemical fertilizers.

ПРИМЕНЕНИЕ МИНЕРАЛЬНЫХ УДОБРЕНИЙ И УРОЖАЙНОСТЬ САХАРНОЙ СВЕКЛЫ В УСЛОВИЯХ БУИНСКОГО МУНИЦИПАЛЬНОГО РАЙОНА РЕСПУБЛИКИ ТАТАРСТАН

The article presents the results of an agroecological assessment of the use of mineral fertilizers on sugar beet crops in the Buinsky municipal district over the past eight years (2015-2022). The scientific novelty lies in considering the issue of statistical processing of actual data on sugar beet yields and the level of application of mineral fertilizers for this crop in relation to a specific municipal district, which certainly has practical significance when making management decisions, determining the structure of the specific composition of mineral fertilizers. As a result of the study, the dependence of sugar beet yield on the amount of the main types of mineral fertilizers applied for the period from 2015 to 2022 was analyzed. Correlation analysis of sugar beet yield and the amount of various types of mineral fertilizers applied to this crop revealed the dependence of yield on the amount of potash fertilizers applied.Next, the formula for regression analysis of the dependence of sugar beet yield on the amount of potassium-containing mineral fertilizers was determined. Regression and correlation analyses of sugar beet cultivation have shown that the level of natural fertility of arable soils in the Buinsky district provides only 20 t/ha of root crops. The application of mineral fertilizers ensures the production of 35,5 t /ha of sugar beet. The increase in yield at the same time will be 15,5 t/ ha. The closest relationship between the increase in yield and nutrition elements was observed in potassium-containing fertilizers (coefficient 0.45). A slight tightness of dependence on the Cheddock scale was noted between an increase in yield and the level of application of nitrogen and phosphorus fertilizers (0.08 and 0.11). This causes the fact that the soils under sugar beet are highly fertile and well provided with these nutrients.

Community composition and physiological plasticity control microbial carbon storage across natural and experimental soil fertility gradients

Many microorganisms synthesise carbon (C)-rich compounds under resource deprivation. Such compounds likely serve as intracellular C-storage pools that sustain the activities of microorganisms growing on stoichiometrically imbalanced substrates, making them potentially vital to the function of ecosystems on infertile soils. We examined the dynamics and drivers of three putative C-storage compounds (neutral lipid fatty acids [NLFAs], polyhydroxybutyrate [PHB], and trehalose) across a natural gradient of soil fertility in eastern Australia. Together, NLFAs, PHB, and trehalose corresponded to 8.5–40% of microbial C and 0.06–0.6% of soil organic C. When scaled to “structural” microbial biomass (indexed by polar lipid fatty acids; PLFAs), NLFA and PHB allocation was 2–3-times greater in infertile soils derived from ironstone and sandstone than in comparatively fertile basalt- and shale-derived soils. PHB allocation was positively correlated with belowground biological phosphorus (P)-demand, while NLFA allocation was positively correlated with fungal PLFA : bacterial PLFA ratios. A complementary incubation revealed positive responses of respiration, storage, and fungal PLFAs to glucose, while bacterial PLFAs responded positively to PO43-. By comparing these results to a model of microbial C-allocation, we reason that NLFA primarily served the “reserve” storage mode for C-limited taxa (i.e., fungi), while the variable portion of PHB likely served as “surplus” C-storage for P-limited bacteria. Thus, our findings reveal a convergence of community-level processes (i.e., changes in taxonomic composition that underpin reserve-mode storage dynamics) and intracellular mechanisms (e.g., physiological plasticity of surplus-mode storage) that drives strong, predictable community-level microbial C-storage dynamics across gradients of soil fertility and substrate stoichiometry.

THE STUDY OF SOIL EROSION UNDER A SYSTEMIC CONCEPTION

This article aimed to understand how erosion processes can be analyzed from a systemic point of view. Soil erosion is considered here a naturally occurring phenomenon, which can be (and usually is) influenced by human activities, constituting one of the main environmental problems of the planet, in addition to being the main modeling agent of the terrestrial surface. The consequences of the accelerated action of erosion processes are numerous, such as: reduction of natural fertility and productive capacity of soils; silting and pollution of water bodies; impoverishment of rural communities; rural exodus; among many others. Understanding the dynamics of this phenomenon becomes fundamental because a comprehension of a spatio-temporal scope, coupled with the knowledge of the possible problems that may occur with its accelerated performance, provides support for the development of sustainable management. Given that soils are the 'foundation' of the fauna, flora, and mainly of human subsistence, it is a valuable resource. The analytical procedures of this manuscript followed the construction of a system based on a case study, exemplifying how the systemic approach can be developed in the studies of erosive processes. By analyzing soil erosion from a systemic approach, it was possible to observe how the different flows of matter and energy occurred between the variables, explain the importance of understanding erosion processes in an integrated way, and avoid fragmented and reductionist interpretations.

Growth Performance of Photoperiod-Sensitive Rice (Oryza sativa L.) Varieties in Different Soil Types under Rainfed Condition in Cambodia

In Cambodia, rice is predominantly produced in areas with rainfed lowland conditions where photoperiod-sensitive varieties are cultivated. A number of varieties have been released for rainfed lowland areas, and the rice grain yield has reportedly increased by approximately 12% over the past ten years. Moreover, great fluctuations in yield performance have been observed across different soil types of the rainfed ecosystems of Cambodia. Therefore, the present study aimed to analyze the grain yield and stability among ten popular varieties that were released for rainfed lowland ecosystems across the four different soil types in Cambodia in two years. The grain yield varied 566 g m−2 as the highest in clay soil and about 220 g m−2 as the lowest in sandy soil. A combined ANOVA revealed significant differences for the main effect of genotype, environment, and genotype-by-environment interaction (GEI) for all yield-related traits and grain yield per square meter. The principal component test results showed that the heterogeneity of grain yield was mainly attributable to the effect of environment, followed by the effect of genotype. In fertile conditions, a higher percentage of filled grains was supported by higher leaf N until the late stage with a wider flag leaf. In conditions of moderate fertility, larger numbers of panicles were supported by a higher percentage of productive culms with higher leaf N until the late stage. In conditions of poor fertility, a higher percentage of filled grains was supported by higher leaf N until the late stage, which is considered to be important for higher grain yield. The variety Phka Rumduol showed these preferable traits and produced higher yields in fertile to poor natural soil fertility conditions with moderate variation. This variety is considered to be more desirable and ideal due to its stability and higher grain yield. The other varieties, namely, Phka Mealdei, Phka Rumdeng, and CAR4, were identified as above-average yielders. Therefore, those varieties potentially may be recommended for cultivation in rainfed lowland rice ecosystems in Cambodia due to their high yields. CAR4 showed moderate variation at the same level as Phka Rumduol. From the point of stability, Phka Rumduol and CAR4 can be expected to excel.

The Use of Faba Bean Cover Crop to Enhance the Sustainability and Resiliency of No-Till Corn Silage Production and Soil Characteristics

Sustainable corn production requires a dramatic shift toward natural soil fertility rather than relying solely on synthetic fertilizers. Cover crops play an important role in improving the productivity of subsequent row crops through improving soil properties. The main goal of this study was to investigate if increasing cover crop biomass through applying a higher density can enhance soil characteristics in the short term and contribute more nitrogen to succeeding corn silage. In a two-year field study (2018–2019), the influence of faba bean (Vicia faba L.) as a cover crop on soil characteristics and corn silage (Zea mays L.) production was evaluated. Treatments consisted of five levels of faba bean density (0, 25, 35, 40, and 80 plants m−2) and four application rates of urea-based nitrogen fertilizer (0, 100, 200, and 300 kg ha−1) in a no-till system. The measured soil characteristics were not significantly affected through increasing cover crop density to 80 plants m−2. The faba bean roots comprised 33% of total biomass in densities ranging from 25–40 plants m−2. The highest total N yield (root + shoot) was 133 kg N ha−1, obtained from 40 faba bean plants m−2. The faba bean root decomposed faster than the shoot, and the addition of N to the corn accelerated 50% N release from the roots but had no significant effect on shoot decomposition. Corn planted after 40 plants m−2 faba bean yielded 28% more than the corn with no faba bean. Corn yielded less in no-cover-crop fields even when it received the highest synthetic N rate (300 kg N ha−1), indicating the value of including faba bean in rotation with corn.

Incorporating cropping systems with eco-friendly strategies and solutions to mitigate the effects of climate change on crop production

Agricultural practices account for approximately 13.5% of all human greenhouse gas emissions and are a significant driver of land-use change. As a result, natural soil fertility has been dramatically reduced, impacting agricultural productivity, the environment, and human health. New technologies, such as green technologies, can address these challenges by adjusting agricultural practices. This paper reviews recent research on climate-mitigating agricultural practices in agronomic cropping systems, and to show how they affect crops, pests, and beneficial arthropods. An optimal amount of synthetic fertilizers and agrochemicals are necessary to maintain production costs, while maximizing outputs. There is a need to develop intelligent, responsive, biodegradable, and biocompatible materials to manufacture green, safe, and efficient fertilizers and pesticides. Site-specific nutrient management (SSNM), is an efficient strategy for managing nutrient efficiency. This system employs inorganic and organic supplies, geographical and temporal soil heterogeneity, crop demands of nutrients, and cropping techniques. A practical strategy to exploit the response of plants to abiotic factors, including the duration, extent, and incidence of specific tolerance mechanisms, is to deploy plant-based products (PBPs). Using microbials (MPBs) is a sustainable strategy to promote plant growth and productivity, even under abiotic situations. Further, nanoparticles, such as iron, silicon, silver, and titanium, can boost plant growth and physiological activity in wheat, maize, soybeans, and spinach are excellent alternatives to artificial chemical pesticides, as they are biodegradable and only affect the target species.Pest and predator responses to agricultural techniques require immediate intervention to mitigate against climate change and ensure food security.

Natural fertility and intrinsic fragility of soils in the Brazilian Cerrado

This study aimed to evaluate the attributes of natural fertility and intrinsic fragility of the soils of Ivinhema River Basin (BHI), to subsidize agricultural development projects and environmental control and monitoring bodies. For this purpose, 62 soil samples were collected, at a depth of 0 to 20 cm, in areas of native vegetation belonging to the state of Mato Grosso do Sul – Brazil. The characteristic climate of the study area is of the humid mesothermal subtype (Cfa) without drought. The predominant vegetation is of the Cerrado type and the geological substrate is predominantly composed of the Serra Geral and Caiuá Formation. The samples were air-dried and the physical attributes (sand, silt, and clay) and chemical variables (pH H2O, CaCl2, KCl, ∆pH, Al3+, m%, H + Al, Ca2+, Mg2+, K+, CEC, SB, V%, OC, P, Cu, Fe, Mn, and Zn) were determined according to methodologies in Embrapa's soil analysis methods manual. The data obtained were evaluated by descriptive statistics and principal component analysis. The results showed a great variety of soils inside the basin, whose natural fertility was high for the Leptsol, Regosol, and Nitisol soils, and low for the Argiluvic Plinthosol, Petroplinthic Plinthosol, and Planosol soils. The sandy soils showed lower levels of organic carbon and negative surface loads, which shows less capacity to retain cations essential to plant nutrition and less retention of environmental contaminants if any. Regarding the textural fragility of the soils of BHI, it was possible to verify the high sensitivity of the soil to erosion and susceptibility to the contamination of groundwater or infiltrated water. The data shown in research can fill the gaps of knowledge and/or for adapting conservation practices of agricultural soils that are more susceptible to erosive processes, as well as for environmental control and monitoring bodies and/or studies of area recovery and maintenance of soil fertility.

How do climate and land-use affect soil carbon and nitrogen stocks and the chemical properties of floodplain soils in tropical drylands?

Floodplain soils represent important food production sites worldwide due to their high natural fertility and large carbon (C) storage capacity. In this study, 27 soil profiles, along an aridity gradient, were used to estimate how climate (semi-arid and dry sub-humid) and land-use (agriculture and overgrazing) affect soil C and nitrogen (N) storage and chemical properties of surface horizons in floodplain soils in tropical drylands, northeastern Brazil. The results indicated that soils under dry sub-humid climate (wetter) accumulated 15.1 and 17.0 % more C and N than soils under semi-arid climate (drier), respectively. The Ca2+, Mg2+, K+, Na+, H+ contents and P availability of the soils were favored in the wetter condition. In the land-use analysis, the results indicated that soils under overgrazing showed lower C and N stocks by 35.7 % and 36.7 % respectively, when compared to soils managed under agriculture. Soils under overgrazing presented, on average, 36.0, 44.4 and 26.0 % less Ca2+, K+ and CEC than the soils under agriculture, respectively. For P, both overgrazing and agriculture reduced its availability by 21.2 and 31.4 % respectively, when compared to the forest soil (reference). The significant effect of overgrazing was evident in the reduction of C and N stocks and natural fertility of the floodplain soils. The results of this study can be useful for the correct management and definition of strategies for sustainable uses of floodplain soils in drylands globally.

Influence of fertilizers on the formation of yield and sowing qualities of spring wheat seeds under the conditions of the forest-steppe of the Middle Volga region

Spring wheat is a valuable food and feed crop with a favorable combination of protein and carbohydrates. Breeders are constantly working to create varieties of spring soft wheat that give stable and high yields even under extreme conditions of its cultivation. The use of fertilizers is an important factor in increasing the yield of spring wheat. Wheat is a valuable feed crop, which is widely used as part of compound feed for poultry and pigs. The purpose of the research was to scientifi cally substantiate the choice of the most eff ective method of using liquid mineral fertilizers on the backgrounds of natural soil fertility and application of N16P16K16, their infl uence on the formation of the crop, sowing qualities and yield properties of spring wheat seeds in the forest-steppe of the Middle Volga region. The infl uence of liquid mineral fertilizers on the backgrounds of natural and mineral nutrition on the density of agrocenosis, crop formation, sowing qualities of seeds and their yield properties has been studied. When using liquid forms of complex mineral fertilizers, methods of their application have been identifi ed that positively aff ect the dynamics of plant growth, yield and quality of seed material of spring soft wheat. It was found as a result of the research that in order to form a high yield with the best indicators of sowing qualities and yielding properties of spring wheat seeds of Tulaykovskaya Nadezhda variety under the conditions of the Middle Volga region, it is necessary to observe a set of agrotechnical techniques developed for this region. Against the background of pre–sowing application of fertilizer N16P16K16 (1 centner/ha), seed treatment should be carried out before sowing with the preparation Megamix – Seeds (2 l/t) followed by non-root fertilizing in the phases “tillering” and “ear formation” with the preparation Megamix – Profi (1 l/ha).