Soil Biological Properties Research Articles

Potential organic amendments for improving productivity and associated biological properties of low carbon soil

Potential organic amendments for improving productivity and associated biological properties of low carbon soil

Innovative organic nutrient management and land arrangements improve soil health and productivity of wheat (Triticum aestivum L.) in an organic farming system

IntroductionSoil health is vital for ecosystems, but excessive use of fertilizers, chemicals, and irrigation harms soil fertility, leading to reduced yields and degradation. Thus, exploring innovative land arrangements and nutrient management for staple crops such as wheat is essential. Organic farming offers a promising solution. This study hypothesized that an appropriate land arrangement, combined with split applications of farmyard manure (FYM) and liquid organic fertilizer, can enhance wheat productivity while also improving soil health. The objective of this study was to investigate the effects of different sowing methods and organic nutrient management practices on the productivity of wheat and soil health.MethodsThis study aimed to examine the impact of sowing methods and nutrient management practices on soil health and organic wheat productivity during the winter seasons of 2021–22 and 2022–23 at the Organic Farming Unit (Agronomy), Rajasthan College of Agriculture, MPUAT, Udaipur. The experiment was arranged in a split-plot design, with three land arrangements/sowing methods in the main plot and eight nutrient management approaches in the subplots.ResultsConcerning different land arrangements, the furrow irrigated raised bed sowing (FIRB) method resulted in the maximum wheat yield (4.34 t ha−1) compared with flat row sowing and zero tillage sowing. With respect to nutrient management practices, 75% of the recommended dose of N (RDN) through the FYM was basal + 25% RDN with the 1st irrigation + Jeevamrut application at 500 L ha−1 during sowing, and the 1st irrigation + Panchagavya spraying at 5% during the booting stage resulted in the highest grain yield (4.47 t ha−1). Both the zero tillage and FIRB land arrangements resulted in better soil biological activities and microbial counts than did flat sowing. The results indicate that sowing wheat via the FIRB method, with the recommended nitrogen dose applied through split applications of FYM along with liquid organic manures such as Jeevamrut and Panchagavya, can be an excellent option for organic wheat cultivation. This approach can enhance both yield and soil health.ConclusionSeventy-five percent RDN through FYM as a basal + 25% RDN during the 1st irrigation + Jeevamrut at 500 L ha−1 during sowing and the 1st irrigation + spraying of Panchagavya at 5% during the booting stage effectively increased the growth and yield of organic wheat. With respect to land arrangements, both FIRB and zero tillage resulted in better growth, yield, and soil biological properties. The practical utility of this study is the optimization of split applications of FYM and land arrangements for organic wheat cultivation.

Evaluation of Soil Texture, EC, pH and Primary Macro Elements in Five Mango Orchard Soils of Kotri, Sindh, Pakistan

Analysis of soil is a very important practice for evaluating the nutrient status and ultimately establishing the fertilizer application program for soil health, fruit quality and production. The aim of present study was to assess the soil texture, electrical conductivity (EC), pH, and primary macronutrients such as N, P, K at 0-15 and 15-30cm depths from five orchards such as Aijaz farm (Orchard 1), Zardari farm (Orchard 2), Shahnawaz farm (Orchard 3), Ismail farm (Orchard 4), and Malik Azad farm (Orchard 5) of Kotri, Sindh Pakistan. The results indicated that most of the soils were sandy clay loam in textural class. The maximum electrical conductivity was found 0.65 dS m-1 in orchard 5, whereas the lowest electrical conductivity was found as 0.42 dS m-1 in orchard 1 at 15-30cm. All the orchards were found alkaline in nature at both 0-15 and 15-30cm depths. The total N content was found 80% low and 20% adequate at 0-15cm depth and 100% orchards were found low in total N content in soil at 15-30cm depth as compared with standard values. The AB-DTPA-P content in orchards were found 60% marginal and 40% adequate at 0-15cm depth, whereas 20% low, 40% marginal and 40% adequate were found at 15-30cm depth. AB-DTPA-K (mg kg-1) was found 20% low and 80% marginal at 0-15 and 15-30cm depths. Future studies should focus on assessing the soil biological properties, plant analysis, soil interaction mechanism, amended with press mud compost, farmyard manure, biochar, modified biochar, nano-material, minerals and low-cost additives.

Biochar enhances soil interactions and the initial development of sugarcane.

The present study evaluated the effects of biochar derived from sugarcane straw on the physicochemical and biological properties of soil and the initial development of sugarcane. Microcosm and pot experiments were conducted over 60 days to monitor variables such as pH, water retention capacity, microbial activity, initial growth, and the metabolomic profile of the plant leaves. The results indicated that biochar increased the soil water retention capacity without significantly affecting the pH. The biochar significantly promoted root length and mass and favored the growth of the soil microbiota, as reflected by an increase in the amount of microbial biomass carbon. Metabolomic analysis of sugarcane leaves revealed that soil conditioning with biochar at application rates of 3 and 5% w/w led to increased concentrations of the amino acids isoleucine and valine, accompanied by a reduction in galactose, maltose, and glucose levels. Furthermore, biochar treatment resulted in a decrease in aconitic acid and an increase in acetic and succinic acid concentrations. These findings suggest that biochar may be a promising strategy for enhancing the productivity and sustainability of sugarcane cultivation.

Long-term changes in soil biological activity and other properties of raised beds in Longan orchards

Introduction The Longan fruit tree of the Vietnam Mekong Delta is grown in raised beds to improve water drainage during the rainy season and can live as long as 100 years. Objective This research explores the extent to which the soil microorganisms as well as soil physical and chemical properties of these raised beds degrade over a period of 60 years under traditional management practices. Materials and Methods Raised bed topsoil samples at depths of 0–20 cm were obtained from four different Longan orchards raised bed age groups: group 1) 15–25 years (L1–L5); group 2) 26–37 years (L6–L10); group 3) 38–45 years (L11–L15); and group 4) 46–60 years. Soil biological properties were tested for nitrogen-fixing bacteria, phosphorus solubilizing bacteria, potassium solubilizing bacteria, calcium solubilizing bacteria and silicate solubilizing bacteria, β-glucosidase, urease, phosphomonoesterase, and phytase. Soil samples were also tested for moisture content, soil texture, soil porosity, and bulk density as well as soil chemical properties including pH, electrical conductivity (EC), soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (NH4+, NO3−), available phosphorus (AP), exchangeable potassium (K+), exchangeable calcium (Ca2 +), available silicate (SiO2), available copper (Cu), zinc (Zn), boron (B) and manganese (Mn). Key findings: The results showed that soil moisture, soil porosity, sand content, SOM, TP, TK, available P, exchangeable Ca2 +, available Si, nitrogen fixing bacteria number, β-glucosidase, urease, phosphomonoesterase, and phytase gradually and significantly decreased in the raised bed soil as the Longan orchard increased in age. Pearson correlation analysis between the ages of Longan orchards and soil properties revealed that raised bed ages were positively correlated with soil bulk density, but negatively correlated with soil moisture content, soil porosity, SOM, TN, β-glucosidase, urease, phosphomonoesterase, and phytase. Principal component analysis (PCA) showed Longan yields had a positive correlation with available NO3− but negative correlation with NFB, exchangeable Ca2 +, pH, and available B. These findings reveal that traditional long-term management of Longan trees in raised beds significantly reduce soil organic matter, moisture content, porosity, and soil fertility with impacts on soil microbial numbers and activity within raised bed soils. Future Directions This suggests that more sustainable management practices, such as mulch and cover crops that decrease soil compaction and increase soil organic matter, improve soil porosity, total N, and feed soil microorganisms that are critical to nutrient cycling are needed to improve raised bed soil quality.

Impact of Combining Bio-Inoculants along with Inorganic Fertilizers on Soil Biological Characteristics in Transplanted Rice (Oryza sativa L.) Crop

A field experiment was carried out during the Kharif season in the year 2022 to assess the impact of inorganic fertilizers along with Bio-inoculants on soil biological properties in rice (Oryza sativa L.). The experiment consists of seven treatments viz., T1 Control, T2 100% RDF (150, 60, 40 N2, P2O5, K2O kg ha-1), T3 80% RDF + 10 kg BGA ha-1 Soil application + PSB (Phosphate solubilizing bacteria) 3kg/ha, T4 60% RDF + 10kg BGA ha-1 Soil application + PSB, T5 80% RDF + 500kg Azolla ha-1 Soil application +PSB, T6 60% RDF + 500kg Azolla ha-1 Soil application +PSB and T7 10kg BGA ha-1 Soil application + 500kg Azolla ha-1 Soil application + PSB were comprised in Randomized Block Design with three replication. The incorporation of inorganics, Azolla PSB, and BGA (bio-inoculants) actively activated microbial activities, resulting in a greater increase in the populations of total bacteria, actinomycetes, and fungi was observed throughout all growth stages, regardless of the treatments applied, when compared to their initial densities. This phenomenon supports the notion of a stronger rhizosphere effect. This trend aligns with the rise in organic carbon content. Moreover, soil dehydrogenase, alkaline phosphatase activities, along with microbial biomass carbon, displayed an upward trend in tandem with the progressive growth phases of the rice plant.

Atributos microbiológicos em Latossolo Vermelho cultivado com cana-de-açúcar na região de cerrado do Brasil Central

ABSTRACT The contribution of plant residues throughout the sugarcane cycles favors the increase of organic matter and the activity of microorganisms in the soil, especially in the surface layers. Soil texture also has an important effect on ecological processes and soil quality. In this context, the objective of this study was to evaluate soil biological attributes in different sugarcane cultivation cycles under mechanized harvesting in an Oxisol in the Savanna region of Central Brazil. The study was conducted in commercial areas under sugarcane cultivation during the 2018/2019 season, which were considered homogeneous in terms of soil and climatic conditions, with the source of variation among the areas being the cultivation cycles (C1: one cultivation cycle; C3: three cultivation cycles; C7: seven cultivation cycles) and a savanna vegetation area selected as a reference. Microbiological variables were determined in two layers, 0-0.1 and 0.1-0.2 m. The variables related to microbial biomass and texture were subjected to principal component analysis. Areas with longer sugarcane cultivation cycles show higher proportion of microbial biomass carbon in the total organic carbon in subsurface layers (microbial quotient). The performance of the soil microbial community, as expressed by total organic carbon and microbial biomass nitrogen indicators, was associated with higher presence of clay and silt, i.e., soil particles smaller than 0.02 mm.

Potential of biochar to restoration of microbial biomass and enzymatic activity in a highly degraded semiarid soil

Biochar is an effective material for enhancing soil ecosystem services. However, the specific impacts of biochar on microbial indicators, particularly in degraded soils, remain poorly understood. This study aimed to evaluate the effects of biochar produced from cashew residues and sewage sludge, in a highly degraded soil, on microbial indicators. We analyzed soil chemical composition and microbial biomass C and N, enzyme activity, and stoichiometry. Cashew biochar increased soil respiration, indicating a higher availability of C to microorganisms compared to sewage sludge biochar and a better adaptation of soil microbial communities to C-rich organic material obtained from a native plant. Although the biochar differentially impacted microbial biomass C, both significantly increased N in the microbial biomass. Arylsulphatase activity did not respond to biochar application, while β-glucosidase, urease, and phosphatases showed significant changes with biochar treatments. Importantly, stoichiometry and vector analysis revealed that both types of biochar increased P limitation for soil microbes. Conversely, both biochar alleviated C and N limitations for the soil microbes. Thus, biochar applications in highly degraded soils should be supplemented with external P sources to maintain soil functions, mainly for cashew residues. Our results provide evidence that biochar can restore soil biological properties and enhance the availability of C and N to microorganisms. These findings have significant implications for restoration practices in degraded lands of semiarid regions.

Understanding the effect of cropping system on soil health at the Northwestern Ontario Agricultural Research Station in Canada

Anthropogenic activities impact soil in varying degrees, from preserving natural landscapes to intensive agriculture which among the farm practices that impact the soil are the cropping systems. Information on cropping systems and soil impacts in northern territories is still missing. This study assesses the effect of different cropping systems on soil health -physical, chemical and biological soil properties and indicators of soil health - at the Lakehead Agricultural Research Station [LUARS] in northern Ontario, Canada. The study compares three cropping systems (perennial crops-pasture, grass, and annual crops -wheat, barley, corn, soybeans) and two forest areas (conifer plantation and naturally regenerating mixed wood forest) at LUARS. Soil samples were collected at different depths and analyzed for various indicators using the Cornell Soil Health Assessment framework. The results showed the soil health scores varied among cropping systems, with natural forest and perennial crops-pasture having higher scores compared to annual crops -wheat, barley, corn, soybeans. Soil organic matter was found to be lowest in annual crops -wheat, barley, corn, soybeans, while aggregate stability was highest in natural forests. The study also identifies the soil health gap, which represents the difference between the health of a particular cropping system and a benchmark. The soil health gap analysis can help farmers implement practices to improve soil health and increase the resilience and sustainability of agroecosystems. Overall, this study emphasizes the importance of understanding the effect of cropping systems on soil health and provides insights into potential strategies for improving farm practices.

Temperate Soils Exposed to Drought—Key Processes, Impacts, Indicators, and Unknowns

The summer drought in the United Kingdom (UK) in 2022 produced significant speculation concerning how its termination may impact and interact with the soil resource. Whilst knowledge regarding soils and droughts exists in the scientific literature, a coherent understanding of the wider range of impacts on soil properties and functions has not been compiled for temperate soils. Here, we draw together knowledge from studies in the UK and other temperate countries to understand how soils respond to drought, and importantly what and where our knowledge gaps are. First, we define the different types of droughts and their frequency in the UK and provide a brief overview on the likely societal impacts that droughts place on the soil and related ecosystems. Our focus is on ‘agricultural and ecosystem drought’, as this is when soils experience dry periods affecting crops and ecosystem function, followed by rewetting. The behaviour of moisture in soils and the key processes that contribute to its storage and transport are examined. The principal changes in the physical, chemical, and biological properties of soils resulting from drought, and rewetting (i.e., drought termination) are discussed and their extensive interactions are demonstrated. Processes that are involved in the rewetting of soils are explored for soil and catchment-scale soil responses. Lastly, soils’ recovery after drought is considered, knowledge gaps are identified, and areas to improve understanding are highlighted.

Soil quality assessment and its response to water flow connectivity in different vegetation restoration types, eastern China

Vegetation restoration is the most widely used forest management practice for degraded soils, but the responses of soil quality in different vegetation restoration types may vary. In addition, the relationship between water flow paths connection and soil quality needs to be further explored. In this study, the soil quality index (SQI) and the index of water flow connectivity (IWFC) in the six water flow patterns (PFP, SSB, WSB, CPS, CPW, and CSW) were explored at three forest stands (oak, pine, and bamboo forests) with 50 years for enclosure. The results showed that the bamboo forest stand had the best soil quality as a whole (0.534 ± 0.135), followed by pine (0.530 ± 0.180) and oak forest stands (0.435 ± 0.205). The IWFC in PFP, CPS and CPW water flow patterns decreased gradually with increasing soil depth, while in SSB, WSB and CSB water flow patterns, the IWFC increased at first and then decreased. Finally, the IWFC in the CPW water flow pattern showed the largest positive correlation with the SQI (P < 0.05). The IWFC in the CPW water flow pattern driven by soil physical properties could mainly control the changes in the SQI indirectly (average IE = 0.825) by influencing soil nutrient (average IE = 0.447) and biological (average IE = 0.485) properties, while its direct effects could be ignored (average DE = −0.074), which demonstrated that the joint effects of preferential flow paths and weak stream buffer zones can dramatically reflect the changes in soil quality. The better soil improvement effect of bamboo and pine forest stands compared to the oak forest stand should be given more consideration. This study provided new insights for the assessment of the relationship between soil hydrology and soil quality.

Biofertilizers: A sustainable strategy for enhancing physical, chemical, and biological properties of soil

A biofertilizer is a biologically derived substance that can enhance soil fertility. It is beneficial for enhancing soil fertility by introducing microorganisms that produce organic nutrients and perhaps decreasing plant illnesses. An extensive review was done to examine the efficacy of several biofertilizers in improving soil properties, including their physical, chemical, and biological characteristics. The secondary data and material for the article were gathered from a variety of sources, including government reports, published research papers, reports from various organizations, and pertinent websites that were examined and their conclusions presented. Although biofertilizers have proven to be a very sustainable method for improving soil quality and increasing crop output, there is a lack of extensive research on their effects on soil’s physical, chemical, and biological aspects. This study aims to offer a comprehensive understanding of various biofertilizers and their effects. This investigation indicated that biofertilizers such as Nitrogen-fixing bacteria, phosphate solubilizers, and potassium solubilizers help to increase NPK content in the soil leading to an increase in the productivity of soil. Moreover, biofertilizers help to enhance soil physical properties (soil bulk density, soil moisture, soil temperature, and soil color), chemical properties (soil pH, soil nitrogen content, soil phosphorus content, soil potassium content, and soil organic carbon content), and chemical properties (population of bacteria, fungi, and actinomycetes). Overall, by overcoming the challenges with biofertilizers in agriculture, we can attain agricultural sustainability.

Biological Characterization of Geo-Referenced Soil Samples from Major Rice-Growing Tracts of Southern Kerala

A survey was conducted from January to March 2023 to assess the soil biological fertility index across five agro-ecological units in the rice-growing belts of Southern Kerala. These units included Onattukara sandy loam (AEU 3), Kari soil (AEU 4), Pokkali soil (AEU 5), Southern laterites (AEU 8), and Midland laterites (AEU 9). The study was carried out in the College of Agriculture, Vellayani Thiruvananthapuram. The survey aimed to assess microbial activity and organic carbon content, thereby enhancing our understanding of the biological fertility across these diverse soil types. Twenty geo-referenced surface soil samples @ 0- 15 cm were collected in every AEU by prescribed method. The collected samples were subjected to the characterization of soil biological properties such as dehydrogenase activity, organic carbon, microbial biomass C, microbial biomass N and soil respiratory rate following the standard protocol. The findings showed that organic carbon in AEU 5 with the highest mean value (3.03 %), followed by AEU 4 (2.19 %), AEU 9 (2.01 %), AEU 8 (1.01 %), and AEU 3 (0.56 %). Dehydrogenase activity was highest in AEU 5 (682.54 µg TPF g-1 hr-1), followed by AEU 4, AEU 9, and AEU 8, and lowest in AEU 3 (76.71 µg TPF g-1 hr-1). AEU 5 exhibited the highest microbial biomass carbon and microbial biomass nitrogen activities, while AEU 8 showed the lowest. Soil respiration was highest in AEU 5 and lowest in AEU 3. Based on these soil microbiological indicators, soils were classified into three categories: low, medium, and high fertility. The Biological Fertility Index (BFI) scores indicated favorable conditions in AEU 4 and 5, moderate in AEU 9, and low in AEU 3 and 8. By establishing a comprehensive understanding of soil biological fertility across various agro-ecological units, the research aims to contribute to improved soil health and crop productivity in the region.

Biological Properties Influenced by Different Tree Species in Deep Chambal Ravine of Madhya Pradesh, India

An experiment site planted with different multipurpose trees and their impact on soil biological properties were measured and analyzed. Based on overall growth on biological properties showed that preferred ranking tree species in the following order viz., maximum soil microbial biomass carbon, dehydrogenease acticity and soil respiration were recorded under Moring a oleifera, respectively followed by Albizia lebbeck, Azadirachta indica, Acacia nilotica, Dalbergia sissoo, Terminalia arjuna, Millettia pinnata and Gmelina arborea while Justicia adhatoda was recorded minimum, respectively. Tree stand growth significantly improved the soil biological properties. Thus, A. Moringa oleifera and Albizia lebbeck species are most suitable multipurpose hardy tree species for rehabilitation of medium and deep ravines of Chambal ravines in India.

Биологическая активность горных почв Западного Кавказа после сведения леса

A study of a set of indicators characterizing the ecological state of forest soils in the mountains of the North-Western Caucasus under broad-leaved and mixed forests has been conducted. The aim of the study has been to assess changes in the biological activity of soils of different genesis after deforestation. The objects of the study have been rendzina, gray forest and gray forest-steppe soils of forest and disturbed ecosystems of the Republic of Adugeya at altitudes from 500 to 1635 m above sea level. Logging plots of different ages (from 10 to 40 years old) after deforestation have been considered. The analyzed indicators have included: the content of total and active carbon, the activity of soil enzymes (catalase, invertase, dehydrogenase, urease, phosphatase), the number of bacteria, as well as an integral index of the biological properties of the soil. The correlation of these indicators with hydrothermal conditions, density of soil structure, penetration resistance, medium reaction, hydrolytic acidity, total absorbed bases and other soil parameters has been evaluated. The level of biological activity of soils in logging areas in the low mountains of Adygea depends on the relief and the timing of restoration after deforestation. Even after several decades of restoration of woody vegetation on the slopes of 12–15° there is no complete return of biological activity to the values of Greyic Phaeozem Eutric of the background forest area. 40 years after logging, the integral index of biological properties of gray forest soil is still 17 % lower than in the control plot. The biological activity of post-forest soils can change in three main directions. On steep slopes, with severe disturbance of the soil and vegetation cover due to the operation of heavy machinery, the integral index of the biological properties of soils decreases by 25–40 % or more without a tendency to recovery. At an average level of disturbance in plots with slight slopes, after an initial decrease, the soils are restored to control values. Restorative successions with intensive development of herbaceous flora and the turf process with slight disturbance can lead to an increase in biological activity above the control values in just 2–3 years. Comprehensive biodiognostic studies using an integral index of the biological state of the soil have revealed, in general, increased stability of low-mountain terrain soils (gray forest and forest-steppe) compared to the soils of the middle mountains of Adygea (rendzina soils). The main degradation factor that reduces the biological activity of soils disturbed by logging is erosion.

Effect of Sod Production on Physical, Chemical, and Biological Properties of Soils in North and South China

Lawns play a vital role in urban development, but the impact of sod production on soil properties has always been controversial. In this study, we examined the physical, chemical, and biological properties of sod production bases across different regions and years [including northern China (2.5, 3, 5, 6, 8, 10, 12 years), referred to as N-2.5, N-3, etc., and southern China (3, 10, 11, 14, 17 years), referred to as S-3, S-10, etc.], with tall fescue and Kentucky bluegrass planted in the north and bermudagrass or creeping bentgrass planted in the south. Sod production was found to increase soil bulk density while reducing porosity and field capacity, but these effects did not consistently intensify with longer production periods. Except for available phosphorus and available potassium, other soil nutrients (total carbon, total nitrogen, organic matter, alkali-hydrolyzable nitrogen, etc.) were either unaffected or increased at certain time points (S-11, S-14). Prolonged sod production (S-10, S-17) also boosted microbial content. In northern regions, organic matter and total nitrogen were the key factors influencing microbial community structure, whereas in southern regions, alkali-hydrolyzable nitrogen, electrical conductivity, available potassium, and organic matter were most influential. We also found that crop rotation, sand mulching, and deep plowing could enhance soil nutrient content and microbial activity in sod production.

Soil Microorganism Interactions under Biological Fumigations Compared with Chemical Fumigation.

Biological fumigation, a potential alternative to chemical fumigation, shows a wide range of prospective applications. In this study, we carried out biological fumigation experiments to evaluate its effect on alleviating consecutive cropping problems (CRPs) when compared with chemical fumigation. We designed five treatments, namely, CR (no treatment), LN (chemical fumigation with lime nitrogen), Ta (fumigation with marigold), Ra (fumigation with radish), and Br (fumigation with mustard), for soils for replanting eggplant and measured the crop's growth status, soil bacterial and fungal communities, and soil physicochemical properties. The results showed that the Br and Ra treatments formed similar microbial communities, while the Ta treatment formed unique microbial communities. The genera Olpidiomycota and Rozellomycota could be used as indicator species for the transformation process of soil microbial communities after the Br and Ta treatments, respectively. When compared with the CR and LN treatments, the soil's physicochemical properties were optimized under the Br treatment, and the soil organic matter content increased by 64.26% and 79.22%, respectively. Moreover, under the Br treatment, the soil's biological properties enhanced the bacterial and fungal alpha diversity, and the saprotrophic fungi increased with the depletion of pathotrophic fungi, while some specific probiotic microorganisms (such as Olpidiomycota, Microascales, Bacillus, etc.) were significantly enriched. In contrast, under the Ta treatment, soil nutrient levels decreased and the soil's biological indices deteriorated, whereas the bacterial diversity decreased and the pathogenic fungi increased. Among these three biological fumigation methods, the Br pre-treatment was the best way to alleviate the crop's CRPs and may be a good substitute for chemical fumigation in some situations. However, the Ta treatment also had some risks, such as the loss of land quality and reduced productivity.

The LTAR Grazing Land Common Experiment at Platte River High Plains Aquifer.

The Long-Term Agroecosystem Research (LTAR) network of the United States Department of Agriculture (USDA) consists presently of 18 sites within the contiguous United States that are managed by the Agricultural Research Service (ARS) and its partners. The LTAR network focuses on developing national strategies for more efficient, resilient, and profitable agricultural production systems, improved environmental quality, and enhanced rural prosperity. The Platte River High Plains Aquifer (PRHPA) LTAR site is managed jointly by the University of Nebraska-Lincoln (UNL) and USDA-ARS and is one of the LTAR sites that conduct research on both integrated cropping and grazing systems. The PRHPA region encompasses multiple land resource areas and diverse agricultural production systems. The PRHPA sites, predominantly located in eastern Nebraska, are designated as an integrated system focused specifically on the region's dominant production practices of row crop (corn and soybean), managed pastures, and beef cattle production. Here, we focus on C3 cool-season smooth bromegrass (Bromus inermis Leyss.) pasture grazing systems under prevailing and alternative management practices for the region. The sites evaluate continuous and rotational grazing with and without pasture fertilization (prevailing practices). In an additional treatment, cattle are supplemented with dry distillers grains plus solubles, while manure supplies fertilization (alternative practice). Main measurements at the site evaluate plant and animal productivity, forage quality, greenhouse gas fluxes, and soil physical, chemical, and biological properties. This paper describes the regional characteristics of the PRHPA site, ongoing LTAR research related to pasture and livestock production, stakeholder engagement, and future research plans.

Effects of aerial liming on soil chemical and biological properties in metal contaminated and inaccessible lands in Ontario (Canada).

The manual addition of lime to soil, in addition to tree planting and fertilization have been the dominant strategy described in restoration protocols for ecosystems damaged by acid rain and metal contamination. Investigations on aerial-limed soils in inaccessible lands are limited. The objective of this study was to assess the effects of aerial liming on soil pH, organic matter, microbial biomass, and enzymatic activities, and aboveground plant population quality in metal-contaminated lands in northern Ontario, Canada. Soil samples were collected from three sites around the City of Greater Sudbury with each pair being composed of a reclaimed (areal-limed) site and an adjacent undisturbed (unlimed) area. Soil physico-chemistry, microbial biomass (assessed by Phospholipid fatty acid analysis) and enzymatic activities were analyzed. Soil pH was higher in limed sites compared to unlimed at recently restored sites (Baby Lake and Wahnapitae) but not at the oldest reclaimed site (HWY 80 N). Organic matter was higher in limed areas compared to the unlimed reference site only at most recently reclaimed site at Baby Lake. Aboveground plant population health was visibly improved in limed sites compared to unlimed areas. Metal concentrations of iron (Fe) and arsenic (As), total microbial biomasses, gram-negative bacterial, fungal, and eukaryotic biomasses were all significantly increased in the limed soils compared to the unlimed samples. The same trend was observed for the activities of three of the enzymes tested, β-N-acetylglucosaminidase (BG), aryl sulfatase (AS), and glycine aminopeptidase (GAP). Interestingly, strong positive correlations between the levels of soil organic matter, microbial biomasses, and NAGase and ALP activities were observed. Although expensive, aerial liming is effective in restoring inaccessible sites impacted by smelting operations where other methods cannot easily be used.

Exploring the Potential of Macroalgae for Sustainable Crop Production in Agriculture.

Marine macroalgae, which typically colonize coastal areas, are simple plant organisms. They live on rocks in coastal regions and are classified into red, brown, and green macroalgae. These algae are an important natural resource in agriculture due to their ability to enhance the structural, chemical, and biological properties of soil. Marine macroalgae can be used to produce various biocidal molecules that are effective in controlling plant pathogens. Much of the literature on marine macroalgae and their derivatives focuses primarily on the pharmaceutical field, while their use in agriculture is still considered secondary. However, various studies and experiments have demonstrated their potential to play a significant role in crop protection and enhancement. This review aims to highlight the various applications of macroalgae in plant production. It also emphasizes the biotechnological importance of marine macroalgae derivatives as biofertilizers, molecules for controlling insects and microorganisms, and as plant growth conditioners. Compounds from macroalgae, such as fatty acids, carotenoids, polyphenols, and carbohydrates, are being investigated for their fungicidal, antimicrobial, and antiviral effects against various plant pathogens. Beyond enhancing crop production, macroalgae can also be considered multifunctional bioinoculants suitable for use in organic farming.