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Cropping systems in semiarid regions have frequently relied on continuous tillage and irrigation, but declining groundwater resources have prompted a greater focus on conservation practices to improve soil health and water storage. We compared soil health responses from cotton production systems in semiarid, coarse-textured soils with different crop management strategies under high or low irrigation levels. Management systems included continuous cotton with conventional tillage (CCCT) compared to no-till cotton with a rye cover crop (NTCR) and no-till cotton with a wheat-fallow rotation (NTCW), including high or low irrigation zones within each system. Samples were collected annually from two bulk soil depths (0–10 cm and 10–20 cm) and root-associated soils 7 years after systems were established and continued for 2 years. We found that cropping system, but not irrigation level, altered soil microbial communities and other soil health indicators. Despite variation between study years and sampling zones, the conservation systems had greater soil microbial community size via ester-linked fatty acid methyl ester (EL-FAME or FAME) analysis, extracellular enzyme activities, and soil organic matter than the CCCT system. The NTCW system also had greater arbuscular mycorrhizal fungi FAME abundance. Our study suggests that no-till and conservation strategies such as cover cropping and rotation can improve biological soil health indicators in these sandy semiarid soils even with limited irrigation. [ABSTRACT FROM AUTHOR]

Healthy soils provide the foundation for sustainable agriculture. However, soil health degradation has been a significant challenge for agricultural sustainability and environmental quality in water-limited environments, such as arid and semi-arid regions. Soils in these regions is often characterized by low soil organic matter (SOM), poor fertility, and low overall productivity, thus limiting the ability to build SOM. Soil health assessment frameworks developed for more productive, humid, temperate environments typically emphasize building SOM as a key to soil health and have identified the best management practices that are often difficult to implement in regions with water limitations. This study reviewed existing soil health assessment frameworks to assess their potential relevance for water-limited environments and highlights the need to develop a framework that links soil health with key ecosystem functions in dry climates. It also discusses management strategies for improving soil health, including tillage and residue management, organic amendments, and cropping system diversification and intensification. The assessment of indicators sensitive to water management practices could provide valuable information in designing soil health assessment frameworks for arid and semi-arid regions. The responses of soil health indicators are generally greater when multiple complementary soil health management practices are integrated, leading to the resilience and sustainability of agriculture in water-limited environments. [ABSTRACT FROM AUTHOR]

Dairy manure fertilization is an important practice to return nutrients to agricultural soils, but there is limited knowledge regarding the effect of manure on soil health metrics in semiarid irrigated row crops. The objective of this research was to determine how long‐term dairy manure application affects biological and chemical indicators of soil health in a field experiment in southern Idaho. The treatments were no fertilizer, inorganic fertilizer (IF), and dairy manure applied annually or biennially at rates of 17, 35, and 52 Mg ha–1 on a dry weight basis. Spring soil samples were collected 7 yr after project initiation at depths of 0–15 cm and 15–30 cm and analyzed with soil health metrics that are commonly used to quantify organic matter pools and biological nutrient cycling via enzyme activities and N transformation rates. Soil organic C increased with increasing application rate and more than doubled after 7 yr of annual manure at the highest application rate. In general, C and N pools, enzyme activities, and N transformation rates were greater at 0–15 cm than deeper in the soil profile. Compared with IF, annual and biennial manure treatments had a significant effect on most indicators at both soil depths, which increased with increasing manure application rate. Because of the strong response of the indicators to dairy manure, all were found to be positively and significantly correlated with each other, suggesting that only a small subset of the metrics tested could potentially be used to evaluate the influence of manure on soil health in the region. Core Ideas: Soil health was investigated in a semiarid crop rotation under long‐term dairy manure.Commonly used biological and chemical indicators were evaluated.Soil organic carbon more than doubled after 7 yr of manure.All soil health metrics increased with increasing manure application rate.Indicator responses were greater in topsoil than deeper in the soil profile. [ABSTRACT FROM AUTHOR]

Soil organic matter (SOM) is essential for soil water holding capacity, aggregation, and biodiversity. Little information is available regarding the carbon (C) functional groups carried away in wind eroded sediments away from the source soil. Mid-infrared (MidIR) spectroscopy was used on wind tunnel-blown sediments eroded from a loam soil during the fallow period of different cropping systems and tillage managements in Akron, Colorado. The soil was managed as fallow-winter wheat ( Triticum aestivum L.) under conventional tillage (F–Wct) or no tillage (F–Wnt) and fallow–wheat–corn under no tillage (F–W–Cnt). Two wind eroded sediments were evaluated: fine dust (<35 μm mean dia.) and saltation-size material (<175 μm mean dia.). Our study showed that there is a partition of C groups within wind eroded sediments of different sizes and that they can reflect the tillage management history of soil. The fine dust had higher levels of aliphatic CH (2930 cm −1 ), and clays (3690–3620 cm −1 ). The saltation-sized material showed higher absorbance for quartz from 2000–1800 cm −1 and reduced absorbance from 1250–1050 cm −1 . Both wind eroded sediments showed higher absorbance for –OH/NH groups and aliphatic CH from no-till soil. Finer dust sediments, which travel greater distances from the source soil than saltation size material, can carry away higher levels of aliphatic-carbon compounds and clays with potential negative impacts on SOM quantity and quality, and consequently the sustainability of these agroecosystems. [ABSTRACT FROM AUTHOR]

Abstract: Wind erosion is a soil degrading process that threatens agricultural sustainability and environmental quality globally. Protecting the soil surface with cover crops and plant residues, practices common in no-till and reduced tillage cropping systems, are highly effective methods for shielding the soil surface from the erosive forces of wind and have been credited with beneficial increases of chemical and physical soil properties including soil organic matter, water holding capacity, and wet aggregate stability. Recently, advances in biofuel technology have made crop residues valuable feed stocks for ethanol production. Relatively little is known about cropping systems effects on intrinsic soil erodibility, the ability of the soil without a protective cover to resist the erosive force of wind. We tested the bare, uniformly disturbed, surface of long-term tillage and crop rotation research plots containing silt loam soils in western Kansas and eastern Colorado with a portable field wind tunnel. Total Suspended Particulate (TSP) were measured using glass fiber filters and respirable dust, PM10 and PM2.5, were measured using optical particle counters sampling the flow to the filters. The results were highly variable and TSP emission rates varied from less than 0.5mgm−2 s−1 to greater than 16.1mgm−2 s−1 but all the results indicated that cropping system history had no effect on intrinsic erodibility or dust emissions from the soil surfaces. We conclude that prior best management practices will not protect the soil from the erosive forces of wind if the protective mantle of crop residues is removed. [Copyright &y& Elsevier]

Soil C and N have long been recognized as important indicators of soil productivity. The current low levels of soil C and N of cropland soils have led to interest in sequestering C with reduced tillage cropping systems and the Conservation Reserve Program (CRP). Our objective was to assess agroecosystem effects on soil C and N pools in the Southern High Plains. The agroecosystems included three cotton (Gossypium hirsutum L.) cropping systems, CRP land, and native rangeland (NR). We sampled 0- to 5-, 5- to 10-, 10- to 15-, and 15- to 30-cm soil depths at 12 farm sites in five counties in West Texas. Total soil C and N, particulate organic matter (POM) C and N, natural abundance of carbon-13 isotope (δ13C) of POM and of whole soil, potentially mineralizable C and N, water-extractable carbon (WEC), and extractable ammonium (NH4+) and nitrate (NO3) were determined. Total C and N in the 0- to 30-cm soil profile were 34 Mg C ha-1 and 2.5 Mg N ha-1 for NR, and 23 Mg C ha-1 and 1.9 Mg N ha-1 for cropland systems, respectively. Total soil C and N in CRP land were greater in cropland soils only in the 0- to 5-cm layer, and were 24 Mg C ha-1 and 2.1 Mg N ha-1 in 0 to 30 cm. Labile C and N pools were positively correlated with each other and with total soil C and N. Low soil test P may have limited C and N sequestration in CRP land and NR. Improved management practices are needed to sequester C and N in CRP and conservation-tillage cotton systems in the Southern High Plains. [ABSTRACT FROM AUTHOR]

The Ogallala Aquifer is one of the largest freshwater aquifers in the world. It acts as a valuable resource in agriculture, animal production, and public water supplies across eight Great Plains states. However, with high irrigation demand, low recharge rates across most of the region, and extreme climate variability, the Ogallala Aquifer has become an exhaustible resource. Some areas of the Ogallala Aquifer region (OAR) are challenged with the transition of irrigated crop systems to dryland production and how to select sustainable management practices to conserve water and soil health. The main goal of this review is to identify the role of soil health in adapting to extreme climate variability with reduced irrigated water. We will describe the OAR, define roles of microorganisms and soil organic matter (SOM) in soil health, outline potential soil health indicators and common methodology, and discuss the importance of soil health assessments and management challenges facing the OAR. Information on this arid to semiarid region will aid in future soil health assessments in regions facing similar challenges. [ABSTRACT FROM AUTHOR]