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Growing calls and the need for sustainable agriculture have brought deserved attention to soil and to efforts towards improving or maintaining soil health. Numerous research and field experiments report soil health in terms of physicochemical and biological indicators, and identify different management practices that can improve it. However, the question remains how much of cultivated land has degraded since the dawn of agriculture? What is the maximum or realistically attainable soil health goal? Determination of a benchmark that defines the true magnitude of degradation and simultaneously sets potential soil health goals will optimize efforts in improving soil health using different practices. In this paper, we discuss a new term “Soil Health Gap” that is defined as the difference between soil health in an undisturbed native soil and current soil health in a cropland in a given agroecosystem. Soil Health Gap can be determined based on a general or specific soil property such as soil carbon. Soil organic carbon were measured at native grassland, no-till, conventionally tilled, and subsoil exposed farmlands. Soil Health Gap based on soil organic carbon was in order of no-till < conventional till < subsoil exposed farmland and subsequently, maximum attainable soil health goal with introduction of conservation practices would vary by an existing management practice or condition. Soil Health Gap establishes a benchmark for soil health management decisions and goals and can be scaled up from site-specific to regional to global scale.
Bijesh Maharjan; Saurav Das; Bharat Sharma Acharya. Soil Health Gap: A concept to establish a benchmark for soil health management. Global Ecology and Conservation 2020, 23, e01116 .
AMA StyleBijesh Maharjan, Saurav Das, Bharat Sharma Acharya. Soil Health Gap: A concept to establish a benchmark for soil health management. Global Ecology and Conservation. 2020; 23 ():e01116.
Chicago/Turabian StyleBijesh Maharjan; Saurav Das; Bharat Sharma Acharya. 2020. "Soil Health Gap: A concept to establish a benchmark for soil health management." Global Ecology and Conservation 23, no. : e01116.
Water discharged from active, abandoned and/or reclaimed coal mine sites with relatively higher acidity continues to be a global concern due to variable impacts on the quality of surface water and groundwater. Treatment of such acid mine drainage (AMD) is often complex, costly, and challenging. Towards this end, this review provides an overview of the formation and effects of AMD, reviews prediction and treatment methods, identifies critical research gaps, and explores the associated challenges and opportunities AMD poses for environmental scientists and researchers. Acid drainage occurs through oxidation of sulfide minerals such as pyrite. The main sources of AMD include runoff and seepage from mine rock dumps, open pit mines, stockpiles, tailings, construction rocks, and rock cuts. While different active and passive treatment systems are available to treat AMD, prevention techniques and integrated management approaches could better identify possible risks, abate treatment costs, and reduce eco-hydrological hazards. Also, the coal mining sector could benefit from remote and ground sensing techniques, including the use of unmanned aerial vehicles and hyperspectral imaging for hydrogeochemical investigations. Effective treatment of acid drainage from mine areas reduces material damage, allows resource reuse and recovery, and enables successful post-mine land use. Environmental scientists must, however, design and implement a proper framework to address AMD in a timely manner. While mining and treatment plans may vary with land-use history, climate, topography, hydrogeology, available technology, and socio-political outlooks, environmental scientists, regulatory agencies, and mining companies must make it a priority to form multidisciplinary partnerships, advocate for effective enforcement of discharge standards, encourage performance bonding, and formulate remediation plans.
Bharat Sharma Acharya; Gehendra Kharel. Acid mine drainage from coal mining in the United States – An overview. Journal of Hydrology 2020, 588, 125061 .
AMA StyleBharat Sharma Acharya, Gehendra Kharel. Acid mine drainage from coal mining in the United States – An overview. Journal of Hydrology. 2020; 588 ():125061.
Chicago/Turabian StyleBharat Sharma Acharya; Gehendra Kharel. 2020. "Acid mine drainage from coal mining in the United States – An overview." Journal of Hydrology 588, no. : 125061.
Applying biochar to agricultural soils has been proposed as a means of sequestering C while simultaneously enhancing soil health and agricultural sustainability. However, our understanding of the long‐term effects of biochar and annual versus perennial cropping systems and their interactions on soil properties under field conditions is limited. We quantified changes in soil C concentration and stocks and other soil properties 6 yr after biochar applications to corn (Zea mays L.) and dedicated bioenergy crops on a Midwestern US soil. Treatments were: no‐till continuous corn, Liberty switchgrass (Panicum virgatum L.), and low diversity prairie grasses, 45% big bluestem (Andropogon gerardii), 45% Indiangrass (Sorghastrum nutans) and 10% sideoats grama (Bouteloua curtipendula), as main plots, and wood biochar (9.3 Mg ha‐1 with 63% total C) and no biochar applications as subplots. Biochar‐amended plots accumulated more C (14.07 vs. 2.25 Mg soil C ha‐1) than non‐biochar amended plots in the 0 to 30 cm soil depth but other soil properties were not significantly affected by the biochar amendments. The total increase in C stocks in the biochar‐amended plots was nearly twice (14.07 Mg soil C ha‐1) the amount of C added with biochar 6 yr earlier (7.25 Mg biochar C ha‐1), suggesting a negative priming effect of biochar on formation and/or mineralization of native soil organic C. Dedicated bioenergy crops increased soil C concentration by 79% and improved both aggregation and available water in the 0 to 5 cm soil depth. Biochar did not interact with the cropping systems. Overall, biochar has potential to increase soil C stocks both directly and through negative priming, but in this study had limited effects on other soil properties after 6 yr.
Humberto Blanco‐Canqui; David A. Laird; Emily A. Heaton; Samuel Rathke; Bharat Sharma Acharya. Soil carbon increased by twice the amount of biochar carbon applied after 6 years: Field evidence of negative priming. GCB Bioenergy 2019, 12, 240 -251.
AMA StyleHumberto Blanco‐Canqui, David A. Laird, Emily A. Heaton, Samuel Rathke, Bharat Sharma Acharya. Soil carbon increased by twice the amount of biochar carbon applied after 6 years: Field evidence of negative priming. GCB Bioenergy. 2019; 12 (4):240-251.
Chicago/Turabian StyleHumberto Blanco‐Canqui; David A. Laird; Emily A. Heaton; Samuel Rathke; Bharat Sharma Acharya. 2019. "Soil carbon increased by twice the amount of biochar carbon applied after 6 years: Field evidence of negative priming." GCB Bioenergy 12, no. 4: 240-251.
Current agricultural systems heavily rely on intensive tillage and inorganic fertilizer inputs. This tradition increases the cost of agricultural production and negatively affects agricultural systems and environment. Conservation practices, such as cover crops (CCs) and no-till (NT), could serve as a management approach to promote soil health and agricultural sustainability. There is limited understanding of CCs effect on soil properties, crop growth and yield under different tillage systems in the humid sub-tropical region of the US. This study evaluated the effect of winter cover crops [wheat (Triticum aestivum) and hairy vetch (Vicia villosa)] and different tillage systems [NT and conventional till (CT)] on soil moisture dynamics, plant nutrients, and soybean (Glycine max) growth and yield in a very fine sandy loam soil from winter 2015 to summer 2018. Results showed significant effect of both tillage and cover crops on soil moisture and infiltration rates during soybean production. Average soil moisture content in the 0–15 and 15–30 cm soil depths was 7.9 and 4.3% higher in the CT than in the NT system, respectively. Cover crops increased soil moisture in 0–30 cm depth by 3 to 5% compared to control plots. No-till increased the percolation rate by 20 to 30% at the 20 to 40 cm depth compared to CT. Cover crop biomass yield in 2017 was significantly affected by CC type, tillage system and their interaction. While CCs had no significant impact on soybean height at harvest, CT increased plant height by 25% and 33% compared with NT for 2016 and 2017, respectively. Soybean yield averaged 3.24 Mg ha−1 across years in CT and 3.02 Mg ha−1 in NT system during 2016 to 2018. Vetch tended to produce higher soybean yield compared to wheat and control. Overall, cover crops could improve soil quality and increase crop yield in humid sub-tropical regions, but such effects vary with CCs type and tillage system.
Bharat Sharma Acharya; Syam Dodla; Lewis. A. Gaston; Murali Darapuneni; Jim J. Wang; Seema Sepat; Hari Bohara. Winter cover crops effect on soil moisture and soybean growth and yield under different tillage systems. Soil and Tillage Research 2019, 195, 104430 .
AMA StyleBharat Sharma Acharya, Syam Dodla, Lewis. A. Gaston, Murali Darapuneni, Jim J. Wang, Seema Sepat, Hari Bohara. Winter cover crops effect on soil moisture and soybean growth and yield under different tillage systems. Soil and Tillage Research. 2019; 195 ():104430.
Chicago/Turabian StyleBharat Sharma Acharya; Syam Dodla; Lewis. A. Gaston; Murali Darapuneni; Jim J. Wang; Seema Sepat; Hari Bohara. 2019. "Winter cover crops effect on soil moisture and soybean growth and yield under different tillage systems." Soil and Tillage Research 195, no. : 104430.
Information on the water quality impact of perennial warm‐season grasses (WSGs) when grown in marginal lands as dedicated energy crops is limited. We studied how WSGs affected runoff, sediment, and nutrient losses and related near‐surface soil properties to those of no‐till corn (Zea mays L.) on an eroded soil in southwestern Iowa and a center pivot corner in east‐central Nebraska. The experiment at the eroded soil was established in 2012, and treatments included ‘Liberty’ switchgrass (Panicum virgatum L.) and no‐till continuous corn. The experiment at the pivot corner was established in 2013 with ‘Liberty’ switchgrass, ‘Shawnee’ switchgrass, low‐diversity grass mixture, and corn. We simulated rainfall at 63.5 ± 2.8 mm h−1 for 1 h to portray 5‐yr return periods and measured water erosion in spring 2017. Time to runoff start and runoff depth did not differ between WSGs and corn. On the eroded soil, sediment and nutrient losses did not differ between treatments. At the pivot corner, sediment (0.71 vs. 0.15 Mg ha−1) and PO4–P (0.037 vs. 0.006 kg ha−1) losses were five times higher in corn than in WSGs. Near‐surface soil properties did not differ on the eroded soil, but at the pivot corner, wet aggregate stability was four times higher and residue cover was 34% higher in WSGs than in corn. Water‐stable aggregates were negatively correlated with NO3–N and PO4–P losses. Overall, WSGs can improve water quality in marginally productive croplands, but their effectiveness appears to be site specific. Core Ideas Warm‐season grasses did not reduce runoff depth compared with corn. Warm‐season grasses on a center pivot corner reduced sediment and nutrient loss compared with corn. Sediment loss between corn and switchgrass grown in an eroded soil did not differ. Warm‐season grass effectiveness to reduce water erosion can be site specific.
Bharat Sharma Acharya; Humberto Blanco‐Canqui; Robert B. Mitchell; Richard Cruse; David Laird. Dedicated Bioenergy Crops and Water Erosion. Journal of Environmental Quality 2019, 48, 485 -492.
AMA StyleBharat Sharma Acharya, Humberto Blanco‐Canqui, Robert B. Mitchell, Richard Cruse, David Laird. Dedicated Bioenergy Crops and Water Erosion. Journal of Environmental Quality. 2019; 48 (2):485-492.
Chicago/Turabian StyleBharat Sharma Acharya; Humberto Blanco‐Canqui; Robert B. Mitchell; Richard Cruse; David Laird. 2019. "Dedicated Bioenergy Crops and Water Erosion." Journal of Environmental Quality 48, no. 2: 485-492.
Soil amendments affect various soil properties that influence water and nutrient dynamics in the soil. Thus, appropriate understanding of their influence on some of these soil properties will be helpful to improve water and nutrient use efficiency, while minimizing environmental pollution. In this study, the effect of poultry litter (PL) and pinewood biochar (PBC) on soil water holding capacity (SWHC), plant available water (PAW), unsaturated and saturated water permeability (WP), evaporation, leaching losses of dissolved organic C (DOC), inorganic-N and metals from a very fine sandy loam soil were evaluated. Addition of both PL and PBC significantly increased SWHC, while PAW was increased by PBC and decreased by PL. Amending of soil with PL at 2.5 and 5% w/w increased unsaturated WP rate, while10% PL decreased WP rate. At all three levels PL decreased saturated WP rate of soil by up to 67% compared to control. Pinewood biochar improved unsaturated WP by up to 2.5 times and saturated WP of soil by up to 2.2 times as compared to control. Despite the black color of biochars that increases thermal absorption, PBC treatments had lower evaporation rates than the control. Both PL and PBC extended the drought tolerance of ryegrass compared to control. Soil amended with PL lost appreciable amounts of DOC, inorganic-N and metals. Amending soil with PBC along with PL benefited by significantly minimizing the leaching losses of DOC, NH4+ and heavy metals. Overall, application of PL along with PBC could benefit crop production by improving SWHC, PAW, and drought tolerance while minimizing the non-point source pollution compared to PL only application for very fine sandy loam soils.
Hari Bohara; Syam Dodla; Jim Jian Wang; Murali Darapuneni; Bharat Sharma Acharya; Selim Magdi; Kiran Pavuluri. Influence of poultry litter and biochar on soil water dynamics and nutrient leaching from a very fine sandy loam soil. Soil and Tillage Research 2019, 189, 44 -51.
AMA StyleHari Bohara, Syam Dodla, Jim Jian Wang, Murali Darapuneni, Bharat Sharma Acharya, Selim Magdi, Kiran Pavuluri. Influence of poultry litter and biochar on soil water dynamics and nutrient leaching from a very fine sandy loam soil. Soil and Tillage Research. 2019; 189 ():44-51.
Chicago/Turabian StyleHari Bohara; Syam Dodla; Jim Jian Wang; Murali Darapuneni; Bharat Sharma Acharya; Selim Magdi; Kiran Pavuluri. 2019. "Influence of poultry litter and biochar on soil water dynamics and nutrient leaching from a very fine sandy loam soil." Soil and Tillage Research 189, no. : 44-51.
In the Great Plains of the central United States, water resources for human and aquatic life rely primarily on surface runoff and local recharge from rangelands that are under rapid transformation to woodland by the encroachment of Eastern redcedar (redcedar; Juniperus virginiana) trees. In this synthesis, the current understanding and impact of redcedar encroachment on the water budget and water resources available for non-ecosystem use are reviewed. Existing studies concluded that the conversion from herbaceous-dominated rangeland to redcedar woodland increases precipitation loss to canopy interception and vegetation transpiration. The decrease of soil moisture, particularly for the subsurface soil layer, is widely documented. The depletion of soil moisture is directly related to the observed decrease in surface runoff, and the potential of deep recharge for redcedar encroached watersheds. Model simulations suggest that complete conversion of the rangelands to redcedar woodland at the watershed and basin scale in the South-central Great Plains would lead to reduced streamflow throughout the year, with the reductions of streamflow between 20 to 40% depending on the aridity of the climate of the watershed. Recommended topics for future studies include: (i) The spatial dynamics of redcedar proliferation and its impact on water budget across a regional hydrologic network; (ii) the temporal dynamics of precipitation interception by the herbaceous canopy; (iii) the impact of redcedar infilling into deciduous forests such as the Cross Timbers and its impact on water budget and water availability for non-ecosystem use; (iv) land surface and climate interaction and cross-scale hydrological modeling and forecasting; (v) impact of redcedar encroachment on sediment production and water quality; and (vi) assessment and efficacy of different redcedar control measures in restoring hydrological functions of watershed.
Chris B. Zou; Dirac Twidwell; Christine H. Bielski; Dillon T. Fogarty; Aaron R. Mittelstet; Patrick J. Starks; Rodney E. Will; Yu Zhong; Bharat Sharma Acharya. Impact of Eastern Redcedar Proliferation on Water Resources in the Great Plains USA—Current State of Knowledge. Water 2018, 10, 1768 .
AMA StyleChris B. Zou, Dirac Twidwell, Christine H. Bielski, Dillon T. Fogarty, Aaron R. Mittelstet, Patrick J. Starks, Rodney E. Will, Yu Zhong, Bharat Sharma Acharya. Impact of Eastern Redcedar Proliferation on Water Resources in the Great Plains USA—Current State of Knowledge. Water. 2018; 10 (12):1768.
Chicago/Turabian StyleChris B. Zou; Dirac Twidwell; Christine H. Bielski; Dillon T. Fogarty; Aaron R. Mittelstet; Patrick J. Starks; Rodney E. Will; Yu Zhong; Bharat Sharma Acharya. 2018. "Impact of Eastern Redcedar Proliferation on Water Resources in the Great Plains USA—Current State of Knowledge." Water 10, no. 12: 1768.
Woody plant encroachment has profound impacts on the sustainable management of water resources in water-limited ecosystems. However, our understanding of the effects of this global phenomenon on groundwater recharge at local and regional scales is limited. Here, we reviewed studies related to (i) recharge estimation methods; (ii) mechanisms by which woody plants impact groundwater recharge; (iii) impacts of woody plant on recharge across different soil and geology; (iv) hydrological repercussions of woody plant removal; and (v) research gaps and needs for groundwater studies. We identified six different methods: water balance, water table, isotopes, chloride mass balance, electrical geophysical imaging, and modeling were used to study the impact of woody encroachment on groundwater. Woody plant encroachment could alter soil infiltration rates, soil water storage, transpiration, interception, and subsurface pathways to affect groundwater recharge. The impact is highly variable, with the extent and the magnitude varying across the soil, substrate, plant cover, and topographic locations. Our review revealed mixed effects of woody plant removal on groundwater recharge. Studies of litter interception, root water uptake, soil moisture dynamics, and deep percolation along with the progression of woody plant encroachment are still limited, warranting further experimental studies focusing on groundwater recharge. Overall, information about woody plant encroachment impacts on groundwater resources across a range of scales is essential for long-range planning of water resources.
Bharat Sharma Acharya; Gehendra Kharel; Chris B. Zou; Bradford P. Wilcox; Todd Halihan. Woody Plant Encroachment Impacts on Groundwater Recharge: A Review. Water 2018, 10, 1466 .
AMA StyleBharat Sharma Acharya, Gehendra Kharel, Chris B. Zou, Bradford P. Wilcox, Todd Halihan. Woody Plant Encroachment Impacts on Groundwater Recharge: A Review. Water. 2018; 10 (10):1466.
Chicago/Turabian StyleBharat Sharma Acharya; Gehendra Kharel; Chris B. Zou; Bradford P. Wilcox; Todd Halihan. 2018. "Woody Plant Encroachment Impacts on Groundwater Recharge: A Review." Water 10, no. 10: 1466.
High rates of crop residue removal as biofuel feedstocks could increase losses of non‐point source pollutants, negatively affecting water quality. An alternative to residue removal can be growing dedicated bioenergy crops such as warm season grasses (WSGs) and short‐rotation woody crops (SRWCs). Yet, our understanding of the implications of growing dedicated bioenergy crops on water quality is limited. Thus, we: (i) synthesized and compared the impacts of crop residue removal, WSGs, and SRWCs on water quality parameters (i.e., sediment and nutrient runoff, nutrient leaching), and (ii) identified research gaps for growing dedicated energy crops. Literature indicates that residue removal at rates >50% (residue retention up to 4.71 Mg ha−1) can increase runoff by 7 to 27 mm, sediment loss by 0.3 to 13.5 Mg ha−1, NO3‐N by 0.85 to 2.06 kg ha−1, and sediment‐associated C by 0.5 to 61 kg ha−1 per rainstorm event. Crop residue removal may also increase nutrient leaching. Studies on the impacts of growing WSGs as dedicated bioenergy crops at field scale on water quality parameters are few. However, WSGs when used as conservation buffers reduce losses of sediment by 66 to 97%, nutrients by 21 to 94% and contaminants by 9 to 98%. This suggests that if WSGs were grown as dedicated bioenergy crops at larger scales, they could reduce losses of non‐point source pollutants. Literature indicates that SRWCs can consistently reduce NO3‐N leaching. Because at this point more modeled than field data are available, further research should focus on 1) field data collection from WSGs and SRWCs from marginal lands, 2) growing monoculture or polyculture WSGs, and 3) large‐scale production of energy crops. Overall, dedicated bioenergy crops, particularly WSGs, can reduce losses of non‐point source pollutants compared to residue removal and be an important strategy to improve water quality if grown at larger scales.
Bharat Sharma Acharya; Humberto Blanco‐Canqui. Lignocellulosic‐based bioenergy and water quality parameters: a review. GCB Bioenergy 2018, 10, 504 -533.
AMA StyleBharat Sharma Acharya, Humberto Blanco‐Canqui. Lignocellulosic‐based bioenergy and water quality parameters: a review. GCB Bioenergy. 2018; 10 (8):504-533.
Chicago/Turabian StyleBharat Sharma Acharya; Humberto Blanco‐Canqui. 2018. "Lignocellulosic‐based bioenergy and water quality parameters: a review." GCB Bioenergy 10, no. 8: 504-533.
Information on the spatio-temporal variability of soil moisture in the vadose zone is important to assess groundwater recharge and solute transport in unconsolidated substrate as influenced by biological processes. Time-lapse electrical resistivity imaging (ERI) was used to monitor soil moisture dynamics to a depth of 9 m in a grassland, a grassland encroached by a juniper species (eastern redcedar, Juniperus virginiana), a juniper woodland and an oak forest in the south-central Great Plains, Oklahoma, USA. A site-specific relationship between moisture content and electrical conductivity data was developed for the soil zone, and a perched water zone was monitored at two of the sites. Results showed that (a) change in soil moisture content was linearly correlated to change in electric conductivity in the soil zone; (b) vegetation cover type induced differences in vertical bulk electrical resistivity (ER) profiles and influenced the temporal evolution of soil moisture profiles; and (c) juniper encroachment lowered the water level in the perched groundwater aquifer. Our results suggest land use and vegetation cover type, as opposed to rock properties, controls deep water drainage for the vegetation transition zone. Methods used to measure hydrogeophysical changes, such as ERI, can be used for broader understanding of geological, physical, and biological processes and their links in Earth’s critical zones.
Bharat S. Acharya; Todd Halihan; Chris B. Zou; Rodney Will. Vegetation Controls on the Spatio-Temporal Heterogeneity of Deep Moisture in the Unsaturated Zone: A Hydrogeophysical Evaluation. Scientific Reports 2017, 7, 1 -10.
AMA StyleBharat S. Acharya, Todd Halihan, Chris B. Zou, Rodney Will. Vegetation Controls on the Spatio-Temporal Heterogeneity of Deep Moisture in the Unsaturated Zone: A Hydrogeophysical Evaluation. Scientific Reports. 2017; 7 (1):1-10.
Chicago/Turabian StyleBharat S. Acharya; Todd Halihan; Chris B. Zou; Rodney Will. 2017. "Vegetation Controls on the Spatio-Temporal Heterogeneity of Deep Moisture in the Unsaturated Zone: A Hydrogeophysical Evaluation." Scientific Reports 7, no. 1: 1-10.
Rajan Ghimire; Sushil Lamichhane; Bharat Sharma Acharya; Prakriti Bista; Upendra Man Sainju. Tillage, crop residue, and nutrient management effects on soil organic carbon in rice-based cropping systems: A review. Journal of Integrative Agriculture 2017, 16, 1 -15.
AMA StyleRajan Ghimire, Sushil Lamichhane, Bharat Sharma Acharya, Prakriti Bista, Upendra Man Sainju. Tillage, crop residue, and nutrient management effects on soil organic carbon in rice-based cropping systems: A review. Journal of Integrative Agriculture. 2017; 16 (1):1-15.
Chicago/Turabian StyleRajan Ghimire; Sushil Lamichhane; Bharat Sharma Acharya; Prakriti Bista; Upendra Man Sainju. 2017. "Tillage, crop residue, and nutrient management effects on soil organic carbon in rice-based cropping systems: A review." Journal of Integrative Agriculture 16, no. 1: 1-15.
Plant and soil interact to shape ecosystem properties, processes and services provided. Changes in ecosystem productivity, biogeochemical cycling and plant herbivore interactions have been widely reported when herbaceous plants are replaced by woody plants, but limited information is available on how woody plant encroachment alters temporal dynamics of deep soil moisture and long-term drainage rates in the tallgrass prairie. We quantified soil water content using capacitance probes for a period of four years, and used both chloride mass balance (CMB) and HYDRUS-1D modelling to depict alteration of deep soil water dynamics and long-term drainage rates after Juniperus virginiana (eastern redcedar) encroachment into the tallgrass prairie. Eastern redcedar encroachment resulted in more frequent depletion of soil water at the 80-cm depth. The chloride ion (Cl−) was used to estimate deep drainage rate because of its nonreactive nature. The ion is neither repelled nor absorbed by soil particles and sediments. Mean soil chloride concentration after encroachment was significantly higher than that in tallgrass prairie. The estimated deep drainage rate based on CMB method was 9.0 mm yr.−1 in the tallgrass prairie and 0.3 mm yr.−1 in the encroached site. The cumulative bottom fluxes were 27.5 cm and 17.1 cm in the tallgrass prairie and eastern redcedar encroached sites, respectively for the HYDRUS simulation period 2011–2014. Transformation of tallgrass prairie to eastern redcedar woodland in the rolling hills of the southern Great Plains reduced soil water content, water storage and downward flux of water. Thus, woody plant encroachment into tallgrass prairie has the potential to reduce groundwater recharge in dry sub-humid regions.
Bharat S. Acharya; Younghong Hao; Tyson Ochsner; Chris B. Zou. Woody plant encroachment alters soil hydrological properties and reduces downward flux of water in tallgrass prairie. Plant and Soil 2016, 414, 379 -391.
AMA StyleBharat S. Acharya, Younghong Hao, Tyson Ochsner, Chris B. Zou. Woody plant encroachment alters soil hydrological properties and reduces downward flux of water in tallgrass prairie. Plant and Soil. 2016; 414 (1-2):379-391.
Chicago/Turabian StyleBharat S. Acharya; Younghong Hao; Tyson Ochsner; Chris B. Zou. 2016. "Woody plant encroachment alters soil hydrological properties and reduces downward flux of water in tallgrass prairie." Plant and Soil 414, no. 1-2: 379-391.
Leaf litter interception of water is an integral component of the water budget for some vegetated ecosystems. However, loss of rainfall to litter receives considerably less attention than canopy interception due to lack of suitable sensors to measure changes in litter water content. In this study, a commercially available leaf wetness sensor was calibrated to the gravimetric water content of eastern redcedar (Juniperus virginiana) litter and used to estimate litter interception in a subhumid eastern redcedar woodland in north-central Oklahoma. Under controlled laboratory conditions, a strong positive correlation between the leaf wetness sensor output voltage (mV) and measured gravimetric litter water content (ϴg) was determined: ϴg = (.0009 × mV2) − (0.14 × mV) − 11.41 (R2 = .94, p < .0001). This relationship was validated with field sampling and the output voltage (mV) accounted for 48% of the observed variance in the measured water content. The maximum and minimum interception storage capacity ranged between 1.16 and 12.04 and 1.12 and 9.62 mm, respectively. The maximum and minimum amount of intercepted rain was positively correlated to rainfall amount and intensity. The continuous field measurements demonstrated that eastern redcedar litter intercepted approximately 8% of the gross rainfall that fell between December 16, 2014 and May 31, 2015. Therefore, rainfall loss to litter can constitute a substantial component of the annual water budget. Long-term in situ measurement of litter interception loss is necessary to gain a better estimate of water availability for streamflow and recharge. This is critical to manage water resources in the south-central Great Plains, USA where grasslands are rapidly being transformed to woodland or woody dominated savanna.
Bharat Sharma Acharya; Elaine Stebler; Chris B. Zou. Monitoring litter interception of rainfall using leaf wetness sensor under controlled and field conditions. Hydrological Processes 2016, 31, 240 -249.
AMA StyleBharat Sharma Acharya, Elaine Stebler, Chris B. Zou. Monitoring litter interception of rainfall using leaf wetness sensor under controlled and field conditions. Hydrological Processes. 2016; 31 (1):240-249.
Chicago/Turabian StyleBharat Sharma Acharya; Elaine Stebler; Chris B. Zou. 2016. "Monitoring litter interception of rainfall using leaf wetness sensor under controlled and field conditions." Hydrological Processes 31, no. 1: 240-249.
A study was conducted to detect climate change and variability using climate records and farmers’ perceptions in Chitwan, Nepal, and to evaluate climatic impacts on small-holder agriculture. Forty years of climatic data (1968–2007) from a weather station at the National Maize Research Program, Rampur, and 15 years of rice, maize, and wheat productivity data (1992–2008) from the District Agriculture Development Office, Chitwan were collected and analyzed using non-parametric Mann–Kendall test and regression analysis. Questionnaire survey was conducted on sixty randomly selected households of Chitwan to understand farmers’ perceptions and adaptations in response to changing climate and variability. Occurrence of extreme events and disasters was cross-validated with DesInventer, a disaster database available for Nepal for 1971–2007. There has been no clear trend in the annual and seasonal rainfall of Chitwan during 1970–2007. However, variation in temperature and a significant upward trend for both minimum (p = 0.014) and maximum temperature (p = 0.018) was observed. The occurrence of extreme events and increased variability in temperature has increased the vulnerability of crops to biotic and abiotic stresses and altered the timing of agricultural operations; thereby affecting crop production. Despite growing attempts of local communities to adapt to changing climate and variability, further planned adaptation aimed at a larger scale and longer duration is necessary to sustain the livelihood security of small-holder farmers.
Bibek Paudel; Bharat Sharma Acharya; Rajan Ghimire; Khem Raj Dahal; Prakriti Bista. Adapting Agriculture to Climate Change and Variability in Chitwan: Long-Term Trends and Farmers’ Perceptions. Agricultural Research 2014, 3, 165 -174.
AMA StyleBibek Paudel, Bharat Sharma Acharya, Rajan Ghimire, Khem Raj Dahal, Prakriti Bista. Adapting Agriculture to Climate Change and Variability in Chitwan: Long-Term Trends and Farmers’ Perceptions. Agricultural Research. 2014; 3 (2):165-174.
Chicago/Turabian StyleBibek Paudel; Bharat Sharma Acharya; Rajan Ghimire; Khem Raj Dahal; Prakriti Bista. 2014. "Adapting Agriculture to Climate Change and Variability in Chitwan: Long-Term Trends and Farmers’ Perceptions." Agricultural Research 3, no. 2: 165-174.
Babu Ram Khanal; Shree Chandra Shah; Shrawan Kumar Sah; Chandeshwor Prasad Shriwastav; Bharat Sharma Acharya. Heavy Metals Accumulation in Cauliflower (Brassica Oleracea L. var. Botrytis) Grown in Brewery Sludge Amended Sandy Loam Soil. International Journal of Agricultural Science and Technology 2014, 2, 87 .
AMA StyleBabu Ram Khanal, Shree Chandra Shah, Shrawan Kumar Sah, Chandeshwor Prasad Shriwastav, Bharat Sharma Acharya. Heavy Metals Accumulation in Cauliflower (Brassica Oleracea L. var. Botrytis) Grown in Brewery Sludge Amended Sandy Loam Soil. International Journal of Agricultural Science and Technology. 2014; 2 (3):87.
Chicago/Turabian StyleBabu Ram Khanal; Shree Chandra Shah; Shrawan Kumar Sah; Chandeshwor Prasad Shriwastav; Bharat Sharma Acharya. 2014. "Heavy Metals Accumulation in Cauliflower (Brassica Oleracea L. var. Botrytis) Grown in Brewery Sludge Amended Sandy Loam Soil." International Journal of Agricultural Science and Technology 2, no. 3: 87.
Human urine, rich in plant nutrients, is a readily available fertilizer but limited information is available about the best use of human urine in crop production. A field experiment was carried out in Kathmandu, Nepal during the year 2011 to evaluate the fertilizer value of human urine in different combination and compare the value with compost, urea and their combinations based on plant performance. The experiment was laid out in Randomized complete block design (RCBD) consisting of eight treatments with three replications. Each treatment was fixed to a supply of 100 kg N ha−1. California Wonder, a popular open pollinated sweet pepper (Capsicum annuum L.) variety was selected as an experimental crop. The highest plant height (54.7 cm), number of fruits per plant (9.1), and fruit yield per plant (553.9 g plant−1) were recorded with the plants fertilized with human urine in combination with compost. Human urine supplemented with 50 kg PK ha−1 gave highest fruit weight (67.2 g) and fruit diameter (5.5 cm). Plants fertilized with the combination of human urine and compost showed better growth and yield compared to the application of fertilizer sources alone. The results indicated that the human urine performs better when used in combination with compost, and can be used as a promising fertilizer source in sweet pepper production.
Debendra Shrestha; Arvind Srivastava; Shanta Man Shakya; Janardan Khadka; Bharat Sharma Acharya. Use of compost supplemented human urine in sweet pepper (Capsicum annuum L.) production. Scientia Horticulturae 2013, 153, 8 -12.
AMA StyleDebendra Shrestha, Arvind Srivastava, Shanta Man Shakya, Janardan Khadka, Bharat Sharma Acharya. Use of compost supplemented human urine in sweet pepper (Capsicum annuum L.) production. Scientia Horticulturae. 2013; 153 ():8-12.
Chicago/Turabian StyleDebendra Shrestha; Arvind Srivastava; Shanta Man Shakya; Janardan Khadka; Bharat Sharma Acharya. 2013. "Use of compost supplemented human urine in sweet pepper (Capsicum annuum L.) production." Scientia Horticulturae 153, no. : 8-12.
Grasslands are potential carbon sinks to reduce unprecedented increase in atmospheric CO2. Effect of age (1–4-year-old) and management (slurry, grazing multispecies mixture) of a grass phase mixed crop rotation on carbon sequestration and emissions upon cultivation was compared with 17-year-old grassland and a pea field as reference. Aboveground and root biomass were determined and soils were incubated to study CO2 emissions after soil disturbance. Aboveground biomass was highest in 1-year-old grassland with slurry application and lowest in 4-year-old grassland without slurry application. Root biomass was highest in 4-year-old grassland, but all 1–4-year-old grasslands were in between the pea field (0.81 ± 0.094 g kg−1 soil) and the 17-year-old grassland (3.17 ± 0.22 g kg−1 soil). Grazed grasslands had significantly higher root biomass than cut grasslands. There was no significant difference in the CO2 emissions within 1–4-year-old grasslands. Only the 17-year-old grassland showed markedly higher CO2 emissions (4.9 ± 1.1 g CO2 kg−1 soil). Differences in aboveground and root biomass did not affect CO2 emissions, and slurry application did not either. The substantial increase in root biomass with age but indifference in CO2 emissions across the age and management in temporary grasslands, thus, indicates potential for long-term sequestration of soil C.
Bharat Sharma Acharya; Jim Rasmussen; Jørgen Eriksen. Grassland carbon sequestration and emissions following cultivation in a mixed crop rotation. Agriculture, Ecosystems & Environment 2012, 153, 33 -39.
AMA StyleBharat Sharma Acharya, Jim Rasmussen, Jørgen Eriksen. Grassland carbon sequestration and emissions following cultivation in a mixed crop rotation. Agriculture, Ecosystems & Environment. 2012; 153 ():33-39.
Chicago/Turabian StyleBharat Sharma Acharya; Jim Rasmussen; Jørgen Eriksen. 2012. "Grassland carbon sequestration and emissions following cultivation in a mixed crop rotation." Agriculture, Ecosystems & Environment 153, no. : 33-39.