Affect Soil Health Research Articles

Wheat Straw Incorporation Affecting Soil Carbon and Nitrogen Fractions in Chinese Paddy Soil

Soil organic carbon (SOC) and nitrogen (N) fractions greatly affect soil health and quality. This study explored the effects of wheat straw incorporation on Chinese rice paddy fields with four treatments: (1) a control (CK), (2) a mineral NPK fertilizer (NPK), (3) the moderate wheat straw (3 t ha−1) plus NPK (MSNPK), and (4) the high wheat straw (6 t ha−1) plus NPK (HSNPK). In total, 0–5, 5–10, 10–20, and 20–30 cm soil depths were sampled from paddy soil in China. Compared with the CK, the HSNPK treatment (p < 0.05) increased the C fraction content (from 13.91 to 53.78%), mainly including SOC, microbial biomass C (MBC), water-soluble organic C (WSOC), and labile organic C (LOC) in the soil profile (0–30 cm), and it also (p < 0.05) increased the soil N fraction content (from 10.70 to 55.31%) such as the soil total N (TN) at 0–10 cm depth, microbial biomass N (MBN) at 0–20 cm depth, total water-soluble N (WSTN) at 0–5 and 20–30 cm depths, and total labile N (LTN) at 0–30 cm depth. The primary components of soil LOC and LTN are MBC and MBN. Various soil C and N fractions positively correlated with each other (p < 0.05). The HSNPK treatment promoted the soil MBC, WSOC, and LOC to SOC ratios, and also promoted MBN, WSTN, and LTN to soil TN ratios at a depth of 0–20 cm. To summarize, the application of HSNPK could maintain and improve rice paddy soil quality, which leads to increased rice grain yields.

Elucidating the impact of three metallic nanoagrichemicals and their bulk and ionic counterparts on the chemical properties of bulk and rhizosphere soils in rice paddies

Growing applications of nanoagrichemicals have resulted in their increasing accumulation in agricultural soils, which could modify soil properties and affect soil health. A greenhouse pot trial was conducted to determine the effects of three metallic nanoagrichemicals on several fundamental chemical properties of a rice paddy soil, including zinc oxide nanoparticles (ZnO NPs) and copper oxide nanoparticles (CuO NPs) at 100 mg/kg, and silicon oxide nanoparticles (SiO2 NPs) at 500 mg/kg, as well as their bulk and ionic counterparts. The investigated soil amendments displayed significant and distinctive impact on the examined soil chemical properties relevant to agricultural production, including soil pH, redox potential, soil organic carbon (SOC), cation exchange capacity (CEC), and plant available As. For example, all amendments increased the bulk soil pH at day 47 to some extent, but the increase was substantially higher for SiO32− (37.7%) than other amendments (5.8%–13.7%). Soil Eh was elevated markedly at day 47 after the addition of soil amendments in both the bulk soil (45.9%–74.4%) and rice rhizosphere soil (20.3%–68.9%). CuO NPs and Cu2+ generally exhibited greater impact on soil chemical properties than other agrichemicals. Significantly different responses to soil amendments were observed between bulk and rhizosphere soils, suggesting the essential role of plants in affecting soil properties and their responses to environmental disturbance. Overall, our results confirmed that the tested amendments could have remarkable impacts on the fundamental chemical properties of rice paddy soils.

Quantifying soil organic carbon’s critical role in cereal productivity losses under annualized crop rotations

Understanding the impact of soil degradation on crop productivity is essential for decision-makers to predict agronomic, economic, and environmental outcomes of agricultural operations. Soil organic carbon (SOC) is influenced by the cropping system and affects soil health through its effect on other soil physical, chemical, and biological properties. Data from a 56-year long-term experiment in Uruguay’s Pampa region were analyzed to quantify the effects of soil degradation on wheat (Triticum aestivum L.), and barley (Hordeum vulgare) yields. A significant degree of soil degradation was generated by six rotations with variable annual crop and pasture proportions (0%, 33%, 50%, and 66% of non harvest pasture). Yield records (n = 368) and annual values of 14 explanatory variables containing soil, climatic, and management indicators were evaluated using random forest regressions. Rotation-induced SOC variation ranged from 1.2% to 2.6%, and robust relationships between SOC, soil physical, chemical, and biological properties were established. Over time, yields increased in crop pasture systems but plateaued for the annualized crop rotation (0% pasture). Yield improvements due to agronomic technology advances partly mask soil degradation effects. SOC losses lead to a reduction in yield, even when the SOC level was above 2%. Thus, no critical level of SOC could be determined. SOC interacted with climate indicators to impact yield. This analysis confirms the central role of SOC in yield outcomes beyond nutrient availability, and its potential to represent a wide range of soil functions. Our findings indicate that crop rotations with a higher percentage annual vs. perennial crops negatively impact SOC, associated soil properties, and yield potential.

Lignin reinforced, water resistant, and biodegradable cassava starch/PBAT sandwich composite pieces

Abstract Following the stipulation to replace nondegradable plastics with biodegradable materials in China, cost-effective and water-resistant packaging materials have become increasingly necessary. In this work, lignin reinforced thermoplastic cassava starch (TPS) pieces were prepared by filling glycerol and lignin powder into starch via a melt blending process and then being pressed into thin pieces. A mechanical properties test showed that following the addition of 3 wt% lignin, the tensile strength of the TPS piece was improved to 16.15 MPa from 3.71 MPa of the original TPS piece. The porous structures of the lignin powder tie the TPS macromolecular chains, induce higher crystallization, and thus provide higher tensile strength and lower elongation at break. After sandwiching two pieces of poly (butylene adipateco-terephthalate) (PBAT)/peanut shell powder composite thin film to each side of the TPS piece, the PBAT/TPS/PBAT sandwich gains excellent water resistance properties. However, as soon as the sandwich piece is cut into smaller ones, they absorb water quickly, implying such pieces can be biodegraded rapidly. These characteristics make it especially suitable for use in the preparation of cabinet waste bags, which are generally stirred into organic fertilizer with the cabinet waste. Slow degradation may negatively affect soil health and farm production.

Road to successful floriculture through soil micronutrient mapping of different zones of India

The present scenario for natural resource conservation demands for crop diversification and efficient management of natural resources, viz. water, nutrient, soil. The horticultural crops are always looked upon for diversification and within horticultural crops; fruits and vegetables are given prime importance for nutritional value and high outputs. Floricultural crops have emerged as potent livelihood crops for small and marginal farmers, employment for youth with low inputs, crop diversification and natural resource management. The improper use of inputs, viz. fertilizer and water in floral crops limits their production and can adversely affect soil health. So floriculturists should work on this least attended area and recommend appropriate fertilizers to flower growers for good quality production. In comparison to other crops, the nutrient requirement of floral crops is more due to which they scavenge more nutrients from soil so large amount of these nutrients are needed to replenish the soil to maintain balance. The critical limits of micronutrients for different agronomic crops have been developed and same are used for floricultural crops too but as requirement of these crops is higher so critical limits for floral crops need to be developed. Keeping in view all above, an attempt has been made to map micronutrient status of major flower producing states that could be used in management of micronutrient requirement of different floral crops. This will further help in development of policies pertaining to sound micronutrient management packages and precision fertilization in floriculture.

Effect of Climate Change on Soil Health and Implications on Food Security: A Review

Climate change and soil health are intertwined complex processes that affect each other. The aim of this review was to find out the impact of climate change on soil health, its implication on food security and human welfare across the globe. The study found out that soil health is affected by land use practices and several anthropogenic activities carried out on landscapes; climate change and variability. Soil health also contributes to soil water retention, crop productivity, households’ food and income security culminating into a large contribution towards achieving sustainable development goals across the globe. Soil components affect climate and climate affects soil health and human wellbeing. The review article concluded that climate change and soil health are complex and intertwined multidisciplinary processes that require multidisciplinary approaches for better understanding and improvement of crop production. Appropriate climate smart agricultural practices are recommended to enhance soil health and mitigate and adapt to the changing climate for the improved farmers’ income, food security and human wellbeing across the globe.

Microplastics in soil: A review on methods, occurrence, sources, and potential risk.

Microplastic is an emerging contaminant of concern in soil globally due to its widespread and potential risks on the ecological system. Some basic issues such as the occurrence, source, and potential risks of microplastics in the soil are still open questions. These problems arise due to the lack of systematic and comprehensive analysis of microplastic in soils. Therefore, we comprehensively reviewed the current status of knowledge on microplastics in soil on detection, occurrence, characterization, source, and potential risk. Our review suggests that microplastics are ubiquitous in soil matrices globally. However, the research progress of microplastics in the soil is restricted by inherent technological inconsistencies and difficulties in analyzing particles in complex matrices, and studies on the occurrence and distribution of microplastics in soil environments remain very scarce, especially in Africa, South America, and Oceania. The consistency of the characteristics and composition of the microplastics in the aquatic environment and soil demonstrate they may share sources and exchange microplastics. Wide and varied sources of microplastic are constantly filling the soil, which causes the accumulation of microplastics in the soil. Studies on the effects and potential risks of microplastics in soil ecosystems are also reviewed. Limited research has shown that the combination and interaction of microplastics with contaminants they absorbed may affect soil health and function, and even migration along the food chain. The occurrence and impact of microplastic on the soil depend on the morphology, chemical components, and natural factors. We conclude that large research gaps exist in the quantification and estimation of regional emissions of microplastics in soil, factors affecting the concentration of microplastics, and microplastic disguising as soil carbon storage, which need more effort.

A chronosequence of soil health under tallgrass prairie reconstruction

Soil health changes induced by prairie reconstruction (cultivated fields to tallgrass prairie) were assessed in Central Missouri within sites representing a chronosequence of 0, 2, 3, 4, 6, 9, 10, 11, 12, and 13-yr post-reconstruction. In addition, a nearby remnant native prairie, two long-term reconstructed prairies (~25 and ~57-yr post-reconstruction), and a biofuel prairie 9-yr post-reconstruction were evaluated for comparative purposes. From 0 to 8-yr, prairie reconstruction increased soil aggregation, total soil organic carbon (SOC), total nitrogen (TN), active C and N (permanganate oxidizable C and total protein), and mineralizable C and N (soil respiration and potentially mineralizable nitrogen), becoming more similar to levels in the remnant prairie. Further, four enzymes involved in the cycling of C (β-glucosidase), N (β-glucosaminidase), P (acid phosphatase), and S (arylsulfatase) demonstrated amplified activities within samples collected to a depth of 15-cm. Over time, the ratios of active C to SOC and active N to TN declined, reflecting the conversion of active C/N pools into more stable C/N pools due to continued organic inputs and increased microbial activity. In contrast, from 8- to 13-yr post-reconstruction, the number of these same soil health indicators declined, which may be attributed to historical land use, the improvement of prairie reconstruction and management strategies, and ecological processes related to succession. Overall, prairie reconstruction holds great potential for soil health restoration in degraded agricultural landscapes, and further study is needed to understand how historical land use and prairie reconstruction practices affect soil health and ecological resilience.

Land Uses, Altitude and Texture Effects on Soil Parameters. A Comparative Study in Two Districts of Nagaland, Northeast India

Northeast (NE) India is a typical tropical ecosystem with a luxuriant forest vegetation cover, but nowadays forests are under stress due to exploitation and land use changes, which are known to affect soil health and productivity. However, due to a scarcity of data, the influence of land uses and altitude on soil properties of this peculiar ecosystem is poorly quantified. This study presents the changes in soil properties in two districts of Nagaland (Mon and Zunheboto) in relation to land uses (forest, plantation, jhum and fallow jhum), altitude (<500 m, 500–1000 m, >1000 m) and soil texture (coarse, medium, fine). For this, a random soil sampling was performed in both the districts. Results indicated that soil organic carbon (SOC) stocks and available potassium (K) were significantly influenced by land uses in the Mon district, while in Zunheboto a significant difference was observed in available phosphorus (P) content. SOC stocks showed an increasing trend with elevation in both districts. The influence of altitude on P was significant and the maximum concentration was at lower elevations (<500 m). In Mon, soil texture significantly affected SOC stocks and the available N and P content. The variability in soil properties due to land uses, altitudinal gradients and textural classes can be better managed with the help of management options, which are still needed for this ecosystem.

Agricultural Soil Management Practices Differentially Shape the Bacterial and Fungal Microbiome of Sorghum bicolor.

Soils play important roles in biological productivity. While past work suggests that microbes affect soil health and respond to agricultural practices, it is not well known how soil management shapes crop host microbiomes. To elucidate the impact of management on microbial composition and function in the sorghum microbiome, we performed 16S rRNA gene and ITS2 amplicon sequencing and metatranscriptomics on soil and root samples collected from a site in California's San Joaquin Valley that is under long-term cultivation with 1) standard (ST) or no tilling (NT) and 2) cover-cropping (CC) or leaving the field fallow (NO). Our results revealed that microbial diversity, composition, and function change across tillage and cover type, with a heightened response in fungal communities, versus bacterial. Surprisingly, ST harbored greater microbial alpha diversity than NT, indicating that tillage may open niche spaces for broad colonization. Across management regimes, we observed class-level taxonomic level shifts. Additionally, we found significant functional restructuring across treatments, including enrichment for microbial lipid and carbohydrate transport and metabolism and cell motility with NT. Differences in carbon cycling were also observed, with increased prevalence of glycosyltransferase and glycoside hydrolase carbohydrate active enzyme families with CC. Lastly, treatment significantly influenced arbuscular mycorrhizal fungi, which had the greatest prevalence and activity under ST, suggesting that soil practices mediate known beneficial plant-microbe relationships. Collectively, our results demonstrate how agronomic practices impact critical interactions within the plant microbiome and inform future efforts to configure trait-associated microbiomes in crops.Importance While numerous studies show that farming practices can influence the soil microbiome, there are often conflicting results on how microbial diversity and activity respond to treatment. In addition, there is very little work published on how the corresponding crop plant microbiome is impacted. With bacteria and fungi known to critically affect soil health and plant growth, we concurrently compared how the practices of no and standard tillage, in combination with either cover-cropping or fallow fields, shape soil and plant-associated microbiomes between the two classifications. In determining not only the response to treatment in microbial diversity and composition, but for activity as well, this work demonstrates the significance of agronomic practice in modulating plant-microbe interactions, as well as encourages future work on the mechanisms involved in community assemblages supporting similar crop outcomes.

Current understanding of subsurface transport of micro‐ and nanoplastics in soil

AbstractEnvironmental problems caused by plastic pollution in terrestrial systems have received increasing attention, especially the issues related to micro‐ and nanoplastics. Soils are a major receptacle and reservoir of plastics, and accumulated plastics can negatively affect soil health. In this short review, we discuss the current state of knowledge of subsurface transport of micro‐ and nanoplastics in soils. We discuss the fundamental transport mechanisms for micro‐ and nanoplastics and highlight the peculiarities of environmentally relevant micro‐ and nanoplastics. Plastic particles >10 μm are generally filtered out in soil, but smaller plastic particles have the potential to move through soil. Larger plastics in soil will break down into micro‐ and nanoplastics over time due to environmental weathering reactions, making the plastics more prone to subsurface transport. Moreover, interactions with microorganisms and dissolved organic matter may render micro‐ and nanoplastics more hydrophilic, thereby facilitating subsurface transport. Further, soil organisms can move plastic particles by bioturbation, and plastics themselves can affect soil hydraulic properties. Although much of the past research has focused on transport of pristine plastic particles, focus should be given to environmentally relevant plastics, considering the complexities of irregular shape, polydisperse size, and heterogenous surface properties, as well as the temporal changes of these properties caused by continuous environmental modifications.

Efficiency of different types of biochars to mitigate Cd stress and growth of sunflower (Helianthus; L.) in wastewater irrigated agricultural soil.

Cadmium contamination in croplands is recognized one of the major threat, seriously affecting soil health and sustainable agriculture around the globe. Cd mobility in wastewater irrigated soils can be curtailed through eco-friendly and cost effective organic soil amendments (biochars) that eventually minimizes its translocation from soil to plant. This study explored the possible effects of various types of plants straw biochar as soil amendments on cadmium (Cd) phytoavailability in wastewater degraded soil and its subsequent accumulation in sunflower tissues. The studied biochars including rice straw (RS), wheat straw (WS), acacia (AC) and sugarcane bagasse (SB) to wastewater irrigated soil containing Cd. Sunflower plant was grown as a test plant and Cd accumulation was recorded in its tissues, antioxidant enzymatic activity chlorophyll contents, plant biomass, yield and soil properties (pH, NPK, OM and Soluble Cd) were also examined. Results revealed that addition of biochar significantly minimized Cd mobility in soil by 53.4%, 44%, 41% and 36% when RS, WS, AC and SB were added at 2% over control. Comparing the control soil, biochar amended soil effectively reduced Cd uptake via plants shoots by 71.7%, 60.6%, 59% and 36.6%, when RS, WS, AC and SB. Among all the biochar, rice husk induced biochar significantly reduced oxidative stress and reduced SOD, POD and CAT activity by 49%, 40.5% and 46.5% respectively over control. In addition, NPK were significantly increased among all the added biochars in soil–plant system as well as improved chlorophyll contents relative to non-bioachar amended soil. Thus, among all the amendments, rice husk and wheat straw biochar performed well and might be considered the suitable approach for sunflower growth in polluted soil.

Response of soil organic carbon and soil health indicators to treated wastewater irrigation in bioenergy sorghum production on an arid soil

AbstractTreated urban wastewater (WW) reuse for crop irrigation is seen as an way to mitigate prolonged drought effects and reduced freshwater (FW) availability for agriculture in arid west Texas. However, the impacts of WW on arid soil health are not clearly understood. This field study evaluated the effects of WW irrigation on soil health indicators including soil organic carbon (SOC), permanganate oxidizable carbon (POXC), mineralizable carbon (MC), and soil protein under bioenergy sorghum production. Water type and gypsum + sulfur application were used as main and subplot factors in a split‐plot experimental design with growth year as a repeated measure. Results across time and soil amendments showed that the SOC of WW‐irrigated soils (3.26 g kg−1) was significantly higher than that of FW‐irrigated soils (2.96 g kg−1). This signifies the positive impact of WW to contribute to soil carbon with no associated priming effects. Wastewater and soil amendment application by themselves did not affect other soil health indicators, given their soil salinization potential. Irrespective of the water type and amendment application, soil POXC significantly increased from 245 to 262 mg kg−1 over time, indicating that a labile pool of C was added to the soil. Soil protein concentrations significantly decreased from 1.31 to 1.23 g kg−1 after 2 years, possibly due to mineralization of organic nitrogen. In conclusion, our results demonstrate that WW application did not adversely affect soil health in the short term. Long‐term studies could provide more insight into the sustained effects of WW irrigation on arid soil health.

Cytogenetic toxicity from pesticide and trace element mixtures in soils used for conventional and organic crops of Allium cepa L.

Pesticides and trace elements occur in complex mixtures in agroecosystems, affecting soil health and food security. Hence, it is necessary to determine their toxicity in field conditions and to develop monitoring approaches to assess conventional and organic agriculture. The aim of this research was to evaluate the associations between Allium cepa L. cytogenetic biomarkers and the realistic mixture of pesticides and trace elements found in soils of conventional, conversion, and organic crops in an intensive agricultural region in Colombia. Pesticide screening was conducted using GC-MS/MS and LC-MS/MS methods. Arsenic, cadmium, lead, and zinc were analyzed by ICP-MS; chromium, copper, nickel, and selenium by ICP-OES; and mercury by a direct analyzer. The meristematic cells in roots of Allium cepa L. were analyzed through microscopic observations to quantify cytogenetic effects. In conventional crops, 26 pesticides were detected in the soil samples, and those were below the limit of quantification in organic crops. The mean levels of As, Cd, Cr, Ni, Pb, and Se were also greater in soils of conventional crops compared to the organics. In addition, the biomarkers of cytotoxicity and genotoxicity appeared augmented in conventional samples, and those were correlated with pesticide and trace element concentrations, pollution indices, and hazard quotients. Subsequently, a discriminant function based on the mitotic index, chromosomal aberrations, and nuclear abnormalities was suitable to classify the samples by crop type. These results demonstrate the sensitivity of Allium cepa L. to the toxicity of complex mixtures in field crops and its potential as an in-situ approach for soil health monitoring in organic and conventional crop systems.

Influence of edaphic and management factors on soils aggregates stability under no-tillage in Mollisols and Vertisols of the Pampa Region, Argentina

In the highly fertile and productive soils of the Pampa Region of Argentina, constraints on soil water regime as a consequence of the decline in aggregates stability and the development of platy structures, are observed. Most of agricultural plots in this region, even under no tillage, are subjected to simplification of crop sequences (low cropping intensity) with predominance of soybean. On the contrary, some farmers are intensifying the crops sequence to avoid soil degradation and equilibrate economical incomes. The aim of this work was to evaluate the effects of intrinsic soil factors and of cropping intensity on aggregates stability in the surface horizon of the main soils in this region. Three Mollisols (an Entic Haplustoll and two Typic Argiudolls) and a Vertisol (Hapludert) located across a west-east transect in the northern part of the Argentinean Pampas were selected for this study. In each site two management treatments under no-till (GAP: Good Agricultural Practices –high cropping intensity- and PAP: Poor Agricultural Practices –low cropping intensity-) and a soil without cultivation as a reference (NE: Natural Environment) were compared. In each treatment, aggregates destruction mechanisms were assessed by Le Bissonnais (1996) tests: slaking, microcraking and cohesion loss. Mollisols showed higher aggregates stability than the Vertisol. Differences on aggregates stability depended on management variables and on organic carbon contents in the Mollisols and on both clay content-clay type in the Vertisol, revealing a strong relationship of aggregation mechanisms with soils taxonomic order. In the Mollisols, the labile coarse particulate organic carbon fraction (POCc) determined the shifts on slaking and overall aggregates stability rather than other carbon fractions. In the soils studied, aggregates stability was linked mainly to management variables, best reflected by the cropping intensity index (CI). More intensive agricultural managements (GAP treatments) in Mollisols and Vertisol, resulted in an enhancement of aggregates stability; however, this relationship was stronger in the Mollisols. Surface horizons from both soil orders evidenced a high soil fragility related to slaking process (FW10s and FW tests). Thus, FW test was the best test to discriminate between management treatments. The results obtained in this work allow, on the one hand, to understand the stabilization mechanisms of the structure in the surface horizon of the main Pampas soils and, on the other hand, to highlight the effect of different NT management practice on soil aggregate stability, which highly affects soil health and the sustainability of agricultural systems.

Earthworm Diversity, Forest Conversion and Agroforestry in Quang Nam Province, Vietnam

The conversion of natural forests to different land uses still occurs in various parts of Southeast Asia with poor records of impact on ecosystem services and biodiversity. We quantified such impacts on earthworm diversity in two communes of Quang Nam province, Vietnam. Both communes are situated within buffer zones of a nature reserve where remaining natural forests are under threat of continued conversion. We identified 25 different earthworm species, out of which 21 were found in natural forests, 15 in agroforestry, 14 in planted forests, and seven each in annual croplands and home gardens. Out of the six species that were omnipresent inhabitants of all observed habitats, Pontoscolex corethrurus largely dominated habitats with intensive anthropogenic activities but was rare in natural forests. Natural and regenerated forests had a much denser earthworm population in the top 10 cm of soil rather than in deeper soil layers. We conclude that the conversion of natural forests into different land uses has reduced earthworm diversity which can substantially affect soil health and ecosystem functions in the two communes. Protection of the remaining natural forests is urgent, while the promotion of a tree-based farming system such as agroforestry can reconcile earthworm conservation and local livelihoods.

Impact of Dairy Wastewater Irrigation and Manure Application on Soil Structural and Water-Holding Properties

HighlightsQuantitative evaluation was performed of dairy waste on soil water-holding capacity.Considering the soil variability on a farm is significant for management practices.Soil aggregate structure plays a pivotal role in studying the impact of waste reuse.Abstract. The livestock sector contributes about 40% of global agricultural output and uses over 30% of total feed-crop land. The sector’s continuing growth has led to increased technology and larger-scale, commercialized agriculture, and it correlates to growth in by-products and waste, which can compromise the environment and human health. Although organic manure is an excellent soil fertilizer whose nutrient content increases crop yield, untreated and/or overapplied manure pollutes local water resources and can alter soil aggregate structure, potentially affecting soil health and available water. Proper livestock waste management is essential for sustainable food production. Waste reuse strategies exist, with goals such as minimizing freshwater consumption, improving food production, and contributing to energy production, However, each strategy has tradeoffs in environmental, energy, or monetary costs. This study provides a quantitative approach to evaluating waste impact on soil health and helps to better manage irrigation practices and water supply gaps in arid and semi-arid areas by better understanding how management practices affect physical soil health. The TypoSoil apparatus was used to measure and analyze the hydrostructural parameters (water-holding capacity and soil structure) of fine sandy loam (A horizon) and sandy clay (B horizon). Soils from the Texas A&M AgriLife Research Dairy (Stephenville, Texas) were collected and compared with control (untouched) soils. Waste (manure, bedding materials, wash water) was separated into liquid (passed through a natural lagoon treatment process) and solid components (applied as fertilizer). Approximately half the wastewater was reused as wash water, the remainder for irrigation. Although the soil varied substantially between sample locations, a statistically significant difference existed between the control and manure/wastewater applications in both the A and B horizons. Both applications improved plant-available water (AW) in the A horizon (40% and 30%, respectively) but deteriorated AW in the B horizon (25% and 30%). Thus, dairy farm waste is a viable source for agricultural use. Keywords: Available water capacity, Pedostructure, Soil health, Soil shrinkage curve, Soil water characteristic curve.

Shifting of microbial biodiversity and soil health in rhizomicrobiome of natural forest and agricultural soil

Abstract Intensive agricultural practices and heavy use of inorganic fertilizers have significantly accelerated soil degradation. Mineralization of the organic matter of soil affects soil health and the abundance of soil beneficial microbes (SBMs) and its dynamics in the soil. The research to investigate the shifting of microbial population and the soil health was conducted in natural forest, agricultural, and degraded ecosystems. The research setting involved randomized block design consisting of six ecosystems, namely, natural forest, agricultural soil (oil palm: 10, 9, 8, and 7 years old), and degraded soils. The soil samples were taken with four replications from rhizomicrobiome of each land use. In the soil health analysis, it was understood that soil beneficial microbes (SBMs) consist of total bacteria, phosphate-solubilizing bacteria, nitrogen-fixing bacteria, total actinomycetes, and total fungi). The results showed that natural forest, oil palm plantation, and degraded land demonstrated a significant effect on the changes in biodiversity of SBM in rhizomicrobiome. The highest population of SBMs was in natural forest followed by the 10-year-old oil palm plantations and the lowest was recorded in degraded soils. These results confirm that the shift of forest ecosystems to agricultural soils will accelerate the degradation and decline of soil health.

Linking Soil Acidity to P Fractions and Exchangeable Base Cations under Increased N and P Fertilization of Mono and Mixed Plantations in Northeast China

Atmospheric N deposition is increasing worldwide, especially in China, significantly affecting soil health, i.e., increasing soil acidification. The northern region of China is considered to be one of the N deposition points in Asia, ranging from 28.5 to 100.4 N ha−1yr−1. Phosphorus (P) is the limiting factor in the temperate ecosystem and an important factor that makes the ecosystem more susceptible to N-derived acidification. However, it remained poorly understood how the soil acidification process affects soil P availability and base cations in the temperate region to increased N deposition. To address this question, in May 2019, a factorial experiment was conducted under N and P additions with different plantations in Maoershan Experimental Forest Farm, Northeast China, considering species and fertilization as variables. The effective acidity (EA) increased by N and NP fertilizations but was not significantly affected by P fertilization. Similarly, the pH, base saturation percentage (BS%), calcium (Ca2+), and magnesium (Mg2+) were decreased under N addition, while the Al:Ca ratio increased, whereas NaHCO3 inorganic phosphorus (Pi) and NaOH organic phosphorus (Po) significantly decreased under N enrichments. However, NaOH Pi increased in N-enriched plots, while H2O Pi and NaHCO3 Pi increased under the P addition. Thus, the results suggest that the availability of N triggers the P dynamics by increasing the P uptake by trees. The decrease in base cations, Ca2+, and Mg2+ and increase in exchangeable Fe3+ and Al3+ ions are mainly responsible for soil acidification and lead to the depletion of soil nutrients, which, ultimately, affects the vitality and health of forests, while the P addition showed a buffering effect but could not help to mitigate the soil acidity.

Effect of integrated use of biochar and organic amendments on soil properties and crop yield

In recent years biochar is found to have positive influence on soil fertility, resulting in an increase in crop yield without affecting soil health and environment. Due to increasing interest towards biochar and organic farming, a field experiment was conducted to evaluate the effect of biochar with different sources of organic amendments on soil properties and yield of knolkhol (Brassica oleracea var. gongyloides L.). The experimental soil showed increase in organic carbon (3.1%), available nitrogen (12.38%), available phosphorus (24.19%), available potassium (8.54%) in treatment containing combined application of FYM, vermicompost and biochar as compare to control. Yield of knolkhol was also highest with the application of manures with biochar over the sole application of amendments.