CONSERVATION TILLAGE AND COVER CROPS FOR IMPROVING SUSTAINABILITY OF SEMIARID DRYLAND CROPPING SYSTEMS IN THE SOUTHWESTERN UNITED STATES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: NEW
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1009434
• Project No.: NMGhimiri-16H
• Project Start Date: Apr 15, 2016
• Project End Date: Mar 31, 2021

Project Director
Ghimire, RA.

Recipient Organization
NEW MEXICO STATE UNIVERSITY
1620 STANDLEY DR ACADEMIC RESH A RM 110
LAS CRUCES,NM 88003-1239

Performing Department
Plant and Environmental Sciences

Non Technical Summary
JustificationThe world population is estimated to reach 9.7 billion by 2050 (United Nations, 2015). This will increase the demand for the world food production by approximately 60% of today. In an effort to increase food, forage, fiber and fuel supply to meet the increasing demand of growing population, soil and environmental quality have been considerably compromised. Typical cropping systems in the drylands of western United States use intensive tillage and long fallow period to conserve moisture for crop production (Nielsen et al., 2005). The intensive tillage-based crop-fallow system has depleted 30-60% of soil organic carbon (SOC) stock in the last century (Brown and Huggins, 2012; Norton et al., 2012; Ghimire et al., 2015). This has also caused loss of biodiversity, depletion of soil nutrients, and increased the problem of wind and water erosion (Stewart et al., 1997). The continuous decline in SOC and nutrients reservoir, biodiversity loss, and erosion negatively influenced agronomic, economic, environmental efficiency of cropping systems and threatened the sustainability of agriculture. Global climate change has added challenges on sustainable food production in the arid and semiarid regions (Lal, 2004). Semiarid agroecosystems near the lower limit of rain-fed crop production are especially vulnerable to changes in climate, input costs, and product prices, yet cover vast areas of the western US and the world (Ghimire et al., 2013). The areas under dryland production is increasing in the western United States including New Mexico because of the depletion in surface and groundwater availability for irrigation (NMDA, 2015). Producers transitioning to dryland production lack information on approaches that enhance the long-term viability, competitiveness, and efficiency in the context of changing climate and increasing economic pressure on them.Agricultural management practices that improve nutrients and water use efficiency, increase SOC sequestration and mitigate greenhouse gas (GHG) emissions while maintaining crop yields can increase sustainability and profitability. Fallow has been practiced to store rainfall during the no-crop period, but the water conservation efficiency of fallowing is extremely low (Nielsen et al., 2005). Instead, extended fallow depletes SOC and increases weed infestation (Stewarts et al., 1997; Ghimire et al., 2015). Conservation systems that reduce or eliminate tillage and uses improved crop, soil, and water management strategies can improve the sustainability of dryland production systems and maximize ecosystem services (Nielsen et al., 2005; Palm et al., 2015). It is not very clear how cropping systems can benefit from conservation systems and other management strategies such as cover cropping in dryland production in the prospect of increasing water limitation, SOC loss, and climate change. This is critical in the semiarid western United States and similar dryland regions across the world where crop production and SOC accrual are constrained by low precipitation and high temperature variation. Improving soil, water, and air quality while sustaining crop yields demand more research on crop and soil management strategies to improve agronomic, economic, and environmental efficiencies in semiarid drylands.Previous work and present outlookInterest in conservation practices including reduced-tillage, crop rotation, and cover cropping has increased to restore soil quality and crop productivity lost due to intensive tillage and crop - fallow system. Alternative management strategies that used cover cropping, crop residues, organic amendments, and followed reduced-tillage management increased SOC accumulation, improved nutrient cycling, and sustained crop yields (Ghimire et al., 2012; Idowu and Grover, 2014; Ghimire et al., 2014a,b; Ghimire et al., 2015). Soils under perennial grasses and no soil disturbance (1931-2010) was able to maintain two times more SOC than conventional winter wheat - fallow system (Ghimire et al., 2015). Reduced-tillage improved agroecosystem performance through an increase in labile SOC components, soil microbial proliferation (Ghimire et al., 2014a) and root growth (Ghimire et al., 2014b). Where perennial cropping or year round cropping is not possible, cover cropping increases biomass production and contributes to SOC accumulation and nutrient cycling (Liebig et al., 2004).Our observations of the ongoing studies at Pendleton OR, previous studies at the central High Plains, as well as literature from other regions revealed that conservation practices such as reduced-tillage, crop rotation, and cover cropping can increase crop yields and improve soil environmental quality. Improved soil management, crop rotations and cover cropping also suppress weeds, insect pests, and diseases. Improving soil, water, and air quality while sustaining crop yields in drylands of the eastern New Mexico, however, should be cautiously considered as high variation in temperature and precipitation limits crop production and biomass turnover. It may take several years to see measurable changes in soil environmental quality and crop performance in this dry environment. There is a knowledge gap regarding impact of alternative tillage, crop rotations, and cover cropping in improving agronomic, economic, and environmental efficiency of dryland cropping systems in the eastern New Mexico and needs additional research.

Animal Health Component

0%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	0110	1070	50%
102	0199	3100	50%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
0110 - Soil; 0199 - Soil and land, general;

Field Of Science
1070 - Ecology; 3100 - Management;

Keywords

no-tillage

strip tillage

cover crop

soil organic matter

dryland farming

Goals / Objectives
Long-term goal: My long-term research goal is to study soil, crop, and water management strategies to improve cropping systems productivity and enhance soil environmental quality. Interdisciplinary studies that evaluate the agronomic, economic and environmental efficiency of cropping systems under different tillage and crop rotations will be examined. Specific objectives are:Objective 1: Evaluate the effects of tillage, crop rotation, and cover cropping in dryland wheat, corn, and sorghum production.Objective 2: Evaluate the influence of tillage, crop rotation, and cover cropping in SOC and nutrient dynamics, and soil water conservation.Objective 3: Determine ecological and economic viability of cover cropping and other conservation strategies in the drylands of western US.

Project Methods
A dryland cropping systems experiment will be established at the New Mexico State University Agricultural Science Center (ASC) at Clovis, NM (34° 35' N, 103° 12' W and altitude of 1,348 m above sea level). The study location is characterized by a semiarid climate with an average annual precipitation of 445 mm, and the mean maximum and minimum temperatures 22 and 7 °C, respectively.Tillage, crop rotations, and cover cropping treatments will be selected in consultation with growers, researchers, and extension educators. Results of the on-going experiments in other parts of the western United States, published research articles, and extension materials from Western SARE, USDA-NRCS, and individual researchers will also be referred to in the decision-making process. The experiment will be established as a three-way split plot experiment. Main plot factor will include crops in the rotation (wheat, corn, and sorghum), the sub-plot factor will be tillage systems (conventional tillage, no-tillage, and strip tillage), and the second sub-plot factor will be cover cropping or no cover cropping. Pea, oat, canola and their mixtures will be used as cover crops. All phases of the rotations will be present each year. Crop performance and soil properties will be monitored periodically to identify crop rotation, tillage, and cover cropping strategies that sustain crop production, improves soil health and increase economic profitability.Objective 1: Crops respond to changes in management practices including tillage, crop rotation, and cover cropping through adjustment in crop growth, development, and yield responses. Phenology of crops will be monitored periodically. Crops will be harvested at physiological maturity using a plot harvester and yield, and yield attributes will be determined. Field scale equipment will be used to harvest the crops in the remaining area. Cover crops will be planted in early spring and harvested in May/June in cover cropping treatments so that it leaves enough moisture for the succeeding crop. Cover crop biomass will be measured by harvesting aboveground biomass in three 1 m x 1 m areas using plot harvesters. Weeds under different crop rotations (dryland wheat, corn, and sorghum), tillage, and cover cropping treatments will be studied by measuring weed population density in a 1m x 1m area of the experimental fields. Measurements will be made in throughout the growing season. Weed biomass will be measured at the end of the growing season.Objective 2: Studies of cropping systems in the drylands of the central and northern High Plains and the Pacific Northwest revealed distinct impacts of conservation tillage, crop rotation, and soil amendments application on SOC and nutrient dynamics, specifically, in recovering SOC lost due to long-term intensive tillage-based production systems (Sherrod et al., 2005; Norton et al., 2012; Ghimire et al., 2015). The response of management changes, however, takes several years to see measurable difference in total SOC and nutrients in drylands and emphasizes need of observing labile and easily decomposable fractions of SOC and N to evaluate early response of management changes in soil quality and crop production (Norton et al., 2012). Six soil cores will be collected in spring, summer, and fall from 0-15 cm depth of each treatment, composited, and analyzed for labile SOC and N pools and other soil properties. The labile SOC and N pools include mineralizable C and N, particulate organic matter C and N, microbial biomass C and N, and inorganic N as nitrate (NO3-) and ammonium (NH4+). Deep cores (0-120 cm) will be collected from each plot at the beginning and end of the experiments using a Giddings probe and the samples will be divided into 0-15, 15-30, 30-60, 60-90 and 90-120 cm depth increments. All soil samples will be analyzed for particle-size distribution, bulk density, pH and electrical conductivity (EC), and SOC and N. Soil inorganic C will be removed by acid treatment. Soil water content will be measured before planting and at two-week intervals until termination of cover crops and until maturity in wheat, corn, and sorghum. Changes in soil water storage, storage efficiency, and water use efficiency will be determined.Objective 3: Using information collected in objective 1 and 2, a multivariate model will be developed to estimate the relative efficiency of production systems and cover cropping practices. The multivariate model will utilize all agronomic and soil quality data to evaluate the relative efficiency of different tillage, crop rotations, and cover cropping to improve agronomic and environmental efficiency of cropping systems. Weather variables such as maximum and minimum temperature and growing season precipitation will also be considered. A complete economic analysis will be conducted to assess the potential of cover cropping and other conservation strategies to improve the economic profitability of dryland and limited irrigation cropping systems. Annual enterprise budgets will be developed for each system. A whole-farm enterprise budget will allow comparisons for both short- and long-term profitability of the alternative systems and provide the ability to perform sensitivity analysis on the results. Short-term profitability examines whether crop revenue can cover the operating costs such as fuel, labor, seed, and repairs. Longer term profitability examines whether there are positive returns to all factors of production, including land and capital. Sensitivity analysis compares results under changing conditions, such as changes in yields or prices for inputs and crops. A robust analysis will provide a range of results to account for uncertainties such as these.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:Growers in eastern New Mexico interested in conservation practices for improving the sustainability of dryland and limited-irrigated cropping systems are the primary target audience. This research will also support USDA Natural Resources Conservation Services, Soil and Water Conservation Society activities. Dryland producers across the world facing soil and water management challenges will be the secondary beneficiaries. Changes/Problems:The year 2020 was unique; field days were canceled due to COVID-19, but I presented research results in several online venues and interacted with producers and other stakeholders. What opportunities for training and professional development has the project provided?A total of six graduatestudents were directly involved in my USDA supported projects leveraged through Hatch funding. Despite the COVID-19 pandemic,area farmers are also trained through online workshops and webinars. How have the results been disseminated to communities of interest?Agriculture Science Center, Clovis organizes field day every year and attracts more than 120 farmers and local stakeholders. The tillage, cover cropping, and land use related studies were disseminated during the field day. Besides, research results were distributed to growers through grower meetings and farmer-researcher interaction forums. The year 2020 was unique; field days were canceled due to COVID-19, but I presented research results in several online venues and interacted with producers and other stakeholders. I work closely with the local USDA-NRCS and Soil and Water Conservation District. The research outcome has been passed along to the producers and policymakers through their channels. We presented posters and gave talks in the Western Society of Crop Science, ASA/CSSA/SSSA Annual Meetings, other local, regional, and international meetings. What do you plan to do during the next reporting period to accomplish the goals?The project is toward its end. All the fieldwork has been done. We will focus on the data analysis and writing reports in the next few months.The dryland tillage study and the limited-irrigation cropping systems research have been concluded. These two projects have provided a foundation for many other projects. The application for the project renewal will be submitted next year and we will continue research, extension, and education activitiesin the next phase of the project.

Impacts
What was accomplished under these goals? Alternative cropping systems and management approaches that reduce or eliminate tillage and use improved crop, soil, and water management strategies were established at the Agricultural Science Center, Clovis, in fall 2015/spring 2016. Winter wheat and winter cover crops are planted in October/November, and spring cover crops are planted in February each year. Cover crops growth, weed population, soil surface temperature, soil water, soil organic matter, and available nitrogen content are monitored periodically.The study results revealed that cover crops used soil moisture and available nutrients, added plant biomass, and improved soil microbial community size and activity. The nutrients utilized by cover crops are released during the subsequent cash crop growth.Comparing tillage systems in a dryland corn-sorghum rotation revealed improvements in agroecosystem carbon balance through reduced-tillage and cover cropping. Economic analysis showed that state and federal governments should provide incentives to farmers adopting cover cropping in semiarid cropping systems. Research results from these projects have been shared with a wider audience through grower meetings, professional conferences, and peer-review journal articles. This is the final year of data collection, data analysis is in progress. We will learn how cover cropping and other conservation tools have worked in the past five years.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Salehin, S.M., R. Ghimire, S. Angadi, and A.O. Mesbah. 2020. Soil organic matter, greenhouse gas emissions, and sorghum yield in semiarid drylands. Agrosystems, Geosciences and Environment. 2020, 3:e20107. https://doi.org/10.1002/agg2.20107.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Ghimire, R., and B.R. Khanal. 2020. Soil organic matter dynamics in semiarid agroecosystems transitioning to dryland. PeerJ 8:e10199 https://doi.org/10.7717/peerj.10199
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Thapa, V.R., R. Ghimire, V. Acosta-Martinez, M. Marsalis, and M. Schipanski. 2021. Cover crop effects on soil microbial community structure and enzyme activities. Applied Soil Ecology. https://doi.org/10.1016/j.apsoil.2020.103735
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Salehin S.M., R. Ghimire, S. Angadi, O.J. Idowu. 2020. Circular grass buffer strips to improve soil health and mitigate greenhouse gas emissions in center-pivot irrigated cropping systems. ASA-CSSA-SSSA Annual Meeting (Virtual), Phoenix, AZ
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Thapa, V.R., R. Ghimire, V. Acosta-Martinez, M. Marsalis, and M. Schipanski. 2020. Cover crop effects on soil microbial community structure and enzyme activities in semiarid cropping systems. ASA-CSSA-SSSA Annual Meeting (Virtual), Phoenix, AZ.

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:Growers in the eastern New Mexico interested in conservation practices for improving the sustainability of dryland and limited-irrigated cropping systems are the primary target audience. Similarly, this research will support USDA Natural Resources Conservation Services, Soil and Water Conservation Society activities. Dryland producers across the world facing soil and water management challenges will be the secondary beneficiaries. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One more graduate students have completed MS degrees focusing on cropping systems and soil management research. A total of four students were directly involved in the USDA supported projects. Project director and graduate students participated in various professional meetings and gained knowledge from these events.Besides, area farmers are also trained by organizing field days, presentation at local meetings, and extension publications. How have the results been disseminated to communities of interest?Agriculture Science Center, Clovis organizes field day every year and attracts more than 120 farmers and local stakeholders. Results of the tillage, cover cropping, and land use related studies were disseminated during the field day. Besides, research results were disseminated to the growers through grower meetings and farmer-researcher interaction forums. We also work closely with local USDA-NRCS, and Soil and Water Conservation District. The research outcome has been passed along to the producers and policymakers through their channels. We presented posters and also gave talks in the Western Society of Crop Science, ASA/CSSA/SSSA Annual Meetings, other local, regional, and international meetings. What do you plan to do during the next reporting period to accomplish the goals?This is the fourth year of the project. The dryland tillage study has been concluded, but the limited-irrigation cropping systems research has been designed to continue for at least six years in the same field. Ongoing research activities will be continued. New projects on forage system and dryland sorghum production have been initiated to address local area needs. Extension materials will be developed for educating area farmers on cover cropping, crop diversification, and conservation tillage strategies. Completed data will be analyzed and results interpreted for presentation in local meetings, field days, professional meetings, and published as a journal paper or extension article. Existing and new graduate students will be trained. We will also continue strengthening the lab and field research works.

Impacts
What was accomplished under these goals? Alternative cropping systems and management approaches that reduce or eliminate tillage and use improved crop, soil, and water management strategies were established at the Agricultural Science Center, Clovis, in fall 2015/spring 2016. Winter wheat and winter cover crops are planted in October/November each year, and spring cover crops are planted in February. Cover crops growth, weed population, soil surface temperature, soil water, soil organic matter, and available nitrogen and phosphorus contents are monitored periodically.Early results of the study revealed that cover crops used soil moisture and available nutrients, added plant biomass, and improved soil microbial community size and activity. The nutrients utilized by cover crops are released during the following main crop growth and support crop production.Comparing tillage systems in a dryland corn-sorghum rotation revealed that reduced-tillage with cover cropping improved agroecosystem carbon balance through their effects on soil organic matter cycling. Economic analysis shows that state and federal government should provide incentives to farmers adopting cover crops in semiarid cropping system to promote environmental services provided by cover crops. Research results from these projects have been shared with a wider audience through grower meetings, professional conferences, and publication of peer review journal articles.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Acharya, R.N., R. Ghimire, A. GC, and D. Blayney. 2019. Effect of cover crop on farm profitability and risk in the Southern High Plains. Sustainability 11(24), 7119. DOI: 10.3390/su11247119.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Thapa, V.R., R. Ghimire, B. Duval, and M. Marsalis. 2019. Soil organic carbon and net ecosystem carbon balance in semiarid cropping systems. Agrosystems, Geosciences, and Environment. Agrosystems, Geosciences & Environment. 2:190022.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Acharya, P., R. Ghimire, and Y. Cho. Linking soil health to crop production: Dairy compost application rates affect soil properties and sorghum biomass. Sustainability 2019, 11, 3552; DOI: 10.3390/su11133552
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Salehin, S.M., R. Ghimire, A. Nilahyane, S. Angadi, O.J. Idowu. 2019. Soil N dynamics and N2O emissions in dryland sorghum field with compost and fertilizer nitrogen application. ASA-CSSA-SSSA International Annual Meetings, San Antonio, TX.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Acharya P., R. Ghimire, and Y. Cho. 2019. Cover crop and compost effects on soil organic matter dynamics: examples from the southern Great Plains region. ASA-CSSA-SSSA International Annual Meetings, San Antonio, TX
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Thapa, V.R., and R. Ghimire. 2019. Soil health in semiarid drylands of eastern New Mexico. SSSA International Annual Meeting, San Diago, CA
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Allan, M., R. Ghimire, C. Brungard, S. Begna, S. Angadi. 2019. Spatial variability of selected soil health indicators in a forage corn production system. SSSA International Annual Meeting, San Diago, CA
• Type: Theses/Dissertations Status: Accepted Year Published: 2019 Citation: Acharya, P. Cover Crops and Dairy Compost Effects on Soil Health and Nutrient Dynamics in Semiarid Southern High Plains. MS Thesis submitted to Eastern New Mexico University

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Growers in the eastern New Mexico interested in conservation practices for improvingthe sustainability of dryland and limited-irrigated cropping systems are the primary target audience. This research will also support USDA Natural Resources Conservation Services and local and regional Soil and Water Conservation Services priorities. Dryland producers across the world facing soil and water management challenges will be the other beneficiaries. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Three graduate studentscompleted the M.S. degree in 2018 under my supervision/co-supervision. These students were directly involved in the USDA supported projects. Besides, area farmers are also trained by organizing field days, presentation at local meetings, and extension publications. Graduated student (co-supervised): Mr. Vesh B. Thapa, M.S. New Mexico State University, Las Cruces, NM. "Tillage and cover crops effects on corn-sorghum rotation." Ms. Mikayla Allan, M.S. New Mexico State University, Las Cruces, NM. "Spatiotemporal variability in soil health parameters". Mr. Apar GC, M.S. New Mexico State University, Las Cruces, NM. "Essays on food security, conflict, and production economics". How have the results been disseminated to communities of interest?Agriculture Science Center, Clovis organizes field day every year and attracts more than 120 farmers and local stakeholders. Results of the tillage, cover cropping, and land use related studies were disseminated during the field day. Besides, research results were disseminated to the growers through grower meetings and farmer-researcher interaction forums. We also work closely with local USDA-NRCS, and Soil and Water Conservation District. The research outcome has been passed along to the producers and policymakers through their channels. We presented posters and also gave talks in Western Society of Crop Science, ASA/CSSA/SSSA Annual Meetings, other local, regional, and international meetings. What do you plan to do during the next reporting period to accomplish the goals?This is the third year of the project. The dryland tillage study has been concluded but the limited-irrigation cropping systems research has been designed to continue for at least six years on the same field. Ongoing research activities will be continued. New projects on forage system and dryland sorghum production have been initiated to address local area needs. Extension materials will be developed for educating area farmers on cover cropping, crop diversification, and conservation tillage strategies. Completed data will be analyzed and results interpreted for presentation in local meetings, field days, professional meetings and published as a journal paper or extension article. Existing and new graduate students will be trained. We will also continue strengthening the lab and field research works.

Impacts
What was accomplished under these goals? Alternative cropping systems and management approaches that reduce or eliminate tillage and use improved crop, soil, and water management strategies were established at the Agricultural Science Center, Clovis in fall 2015/spring 2016. Winter wheat and winter cover crops are planted in October/November each year and spring cover crops are planted in February. Cover crops growth, weed population, soil surface temperature, soil water, soil organic matter, and available nitrogen and phosphorus contents are monitored periodically.Early results of the study revealed that cover crops used soil moisture and available nutrients, added plant biomass, and improved soil microbial activity (measured by in-field CO2 emissions and by laboratory C mineralization study). The nutrients utilized by cover crops are expected to release during the following main crop growth and support crop production.Comparing tillage systems in a dryland corn-sorghum rotation revealed that reduced-tillage management has improved agroecosystem performance through their effects on soil organic matter dynamics and nutrient cycling. On-farm soil sampling, literature synthesis on the opportunities and challenges of integrating cover crops in dryland and limited-irrigation cropping systems in the Eastern New Mexico revealed improvements in soil health and agroecosystem resilience by adopting conservation systems. Research results from these projects have been shared with a wider audience through grower meetings, professional conferences, and publication of peer review journal articles.

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: Thapa, V.R., R. Ghimire, M. Mikha, J. Idowu, and M. Marsalis. 2018. Land use systems effects on soil health in drylands. Agricultural and Environmental Letters. Doi: 10.2134/ael2018.05.0022.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Ghimire, R., B. Ghimire, A.O. Mesbah, M. ONeill, J. Idowu, S. Angadi, and M.K. Shukla. 2018. Current status, opportunities, and challenges of cover cropping for sustainable dryland farming in the Southern Great Plains. Journal of Crop Improvement. 32: 579-598.
• Type: Other Status: Published Year Published: 2018 Citation: Mixing it up: In the Ogallala Aquifer region, one size (of farming) doesnt fit all. TxH2O Fall Newsletter.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Thapa, V.R., and R. Ghimire. 2019. Soil health in semiarid drylands of eastern New Mexico. SSSA International Annual Meeting, San Diago, CA. Thapa V.R., R. Ghimire, V. Acosta-Martinez, and M. Marsalis. 2018. Reducing Tillage and Increasing Crop Diversity for Improving Soil Health and Agricultural Sustainability: Examples from Eastern New Mexico. NM Sustainable Agriculture Conference, Los Lunas, NM. Thapa V.R., R. Ghimire, V. Acosta-Martinez, and M. Marsalis. 2018. Conservation systems for improving soil health and resilience in the southern Ogallala region. Ogallala Water Project third annual meeting, Santa Fe, NM. Ghimire, R., V.R. Thapa, and A.O. Mesbah. 2018. Tillage and cover crops effects on soil organic matter dynamics under dryland corn-sorghum rotation. ASA-CSSA International Annual Meeting, Baltimore, MD. Acharya, P., R. Ghimire, and C. Young. 2018. Soil health indicators under diverse cover crops in a winter wheat-sorghum-fallow rotation. Soil Health Institute third annual meeting, Albuquerque, NM. Ghimire, R., A.O. Mesbah, R.N. Acharya, and M.A. Marsalis. 2018. Cover crops in limited irrigated cropping systems: Opportunities and challenges for sustaining the Ogallala Aquifer. Western Society of Crop Science Annual Meeting, Laramie, WY. Ghimire, B., R. Ghimire, and A.O. Mesbah. 2018. Early responses of cover crops on limited-irrigated winter wheat-sorghum fallow. Global Food Security through Agricultural Transformation. Oklahoma City, OK. Thapa, V.R. and R. Ghimire. 2018. Tillage and cover cropping effects on soil organic matter components and wet aggregate stability in the semi-arid drylands. Global Food Security through Agricultural Transformation. Oklahoma City, OK. Thapa, V.R. and R. Ghimire. 2018. Land use effects on soil organic matter pools and soil structure. NeSA 10th International Conference on Role of Diaspora for Sustainable Homeland, Las Cruces, NM. Thapa, V., R. Ghimire, A.O. Mesbah. 2018. Land use systems effects on soil organic matter and nutrients in drylands of Eastern New Mexico. ACES Open House, NMSU. Thapa, V., R. Ghimire, O.J. Idowu, and A.O. Mesbah. 2018. Soil fertility response to tillage systems and cover cropping in a dryland corn-sorghum rotation. Graduate Student Fair, University Research Council, NMSU.
• Type: Other Status: Published Year Published: 2018 Citation: Ghimire, R. 2018. Sustainably feeding current and future generations. Scientia Global, https://www.scientia.global/dr-rajan-ghimire-sustainably-feeding-current-and-future-generations/

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Growers in the Eastern New Mexico and West Texas are interested in adopting conservation practices for improvingsustainability of dryland and limited-irrigated cropping systems. The farmers interested in conservation systems are the primary target audience. This research will also provide information toUSDA Natural Resources Conservation Services, Soil and Water Conservation Society activities to support growers inconservation practices. Besides, dryland producers across the world facing soil and water management challengescanbenefit from this research. Changes/Problems:Establishment of cover crop in dryland is very challanging. Cover crops established well in 2016/17 in drylands, but it even did not germinate during 207/18. This is also affecting yield and soil quality. What opportunities for training and professional development has the project provided?A co-advised graduate student has completed M.S. degree and two graduate students are being trained under the cropping systems program. Besides, area farmers are also trained by organizing field days, presentation at local meetings, and extension publications. Graduated student (co-supervised): Mr. Binod Ghimire, M.S. 2017. Current graduate students: Mr. Vesh B. Thapa, M.S. New Mexico State University, Las Cruces, NM. Ms. Mikayla Allan, M.S. New Mexico State University, Las Cruces, NM. How have the results been disseminated to communities of interest?Agriculture Science Center, Clovis organizes field day every year and attracts more than 120 farmers, and local stakeholders during this event. Results of the cover crops study was disseminated during the field day. Besides, research results were disseminated to the growers through grower meetings and farmer-researcher interaction forums. We also work closely with local USDA- NRCS, and Soil and Water Conservation District. The research outcome have been passed along to the producers and policy makers through their channels. We presented posters and also gave talks in Western Society of Crop Science, ASA/CSSA/SSSA Annual Meetings, other local, regional, and international meetings. What do you plan to do during the next reporting period to accomplish the goals?This is the second year of the project. The research has been designed to continue for at least five to six years on the same field. Ongoing projects will be continued and the new projects will be initiated to address project goals and objectives. Extension materials will be developed for educating area farmers on cover cropping, crop diversification, and conservation tillage strategies. Completed data will analyzed and results interpreted for presentation in local meetings, field days, professional meetings and published as a journal paper or extension article. Existing and new graduate students will be trained. We will also continue strengthening the lab and field research works.

Impacts
What was accomplished under these goals? Alternative cropping systems that reduce or eliminate tillage and use improved crop, soil, and water management strategies were established at the Agricultural Science Center, Clovis in fall 2015/spring 2016. Winter wheat and winter cover crops are planted in October/November each year and spring cover crops are planted in February. Cover crops growth, weed population, soil surface temperature, soil water, soil organic matter, and available nitrogen and phosphorus contents are monitored periodically.Early results of the study revealed that cover crops used soil moisture and available nutrients, added plant biomass, and improved soil microbial activity (measured by in-field CO2 emissions and by laboratory C mineralization study). We also found that at leastfive ton biomass input is required to maintain SOCin drylands of the Southern High Plains.The nutrients utilized by cover crops are expected to release during the following main crop growth and support crop production.Comparing tillage systems in a dryland corn-sorghum rotation revealed that reduced-tillage management has improved agroecosystem performance through their effects on soil organic matter dynamics and nutrient cycling. Besides, we are conducting some on-farm soil sampling, synthesizing literature, and evaluating opportunities and challenges of integrating cover crops in dryland and limited irrigation cropping systems in the Eastern New Mexico and West Texas. The Cropping Systems and Soil Management laboratory is also expanding facility and resources, which allows us to monitor seasonal and inter-annual dynamics of soil quality indicators that influences crop production and agroecosystem resilience.

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Ghimire, B. R. Ghimire, D. VanLeeuwen and A.O. Mesbah. 2017. Cover crop residue inputs and quality effects on soil organic matter mineralization. Sustainability, 9, 2316. http://www.mdpi.com/2071-1050/9/12/2316.
• Type: Theses/Dissertations Status: Accepted Year Published: 2017 Citation: Ghimire B., Cover crop effects on soil organic matter dynamics, weed suppression and wheat yield in a limited irrigated winter wheat summer fallow system.
• Type: Other Status: Published Year Published: 2017 Citation: Cano, A., A. Nunez, V. Acosta-Martinez, M. Schipanski, R. Ghimire, and C. Rice. 2017. Linking soil health to water conservation in the Ogallala Aquifer region. Colorado Water, special issue  the Ogallala Water, November/December 2017.
• Type: Other Status: Published Year Published: 2017 Citation: Idowu, J., S. Angadi, M.K. Darapuneni, and R. Ghimire. 2017. Reducing tillage in arid and semi-arid cropping systems. NMSU Cooperative Extension Services. Guide A-152. http://aces.nmsu.edu/pubs/_a/A152.pdf
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Ghimire, B., R. Ghimire, and A.O. Mesbah. 2017. Cover crops effect on soil moisture content, organic matter dynamics and wheat yield in a limited-irrigated winter wheat-summer fallow system. NM Sustainable Agriculture conference, Los Lunas NM.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Allan, M.J., R. Ghimire, C. Brungard, and S. Begna. 2017. Understanding soil spatial variability for sustainable corn production in the Eastern New Mexico. NM Sustainable Agriculture conference, Los Lunas NM
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Thapa, V., R. Ghimire, A. Cano, V. Acosta-Martinez, O.J. Idowu, and M. Marsalis. 2017. Soil health under diverse land use systems in the drylands of Eastern New Mexico. Ogallala Water Project second annual meeting, Manhattan KS
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Angadi, S., S. Begna, P.H. Gowda, O.J. Idowu, R. Ghimire, C.P. West. G.W. Marek, J. Stout. 2017. Circular buffer strips of perennial grasses: preliminary assessment. ASA, CSSA, SSSA International Annual Meetings, Tampa, FL
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Ghimire B., R. Ghimire, A.O. Mesbah, D. VanLeeuwen. 2017. Potential soil carbon mineralization and mineralization kinetics under diverse cover crop residues. ASA, CSSA, SSSA International Annual Meetings, Tampa, FL.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Ghimire B., R. Ghimire, A.O. Mesbah. 2017. Soil biochemical responses of cover crops in a winter wheat  summer fallow system. ASA, CSSA, SSSA International Annual Meetings, Tampa, FL
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Ghimire R., B. Ghimire, V.B. Thapa, and A.O. Mesbah. 2017. Soil C and N cycling under reduced tillage and cover crops in the southern High Plains agroecosystems. ASA, CSSA, SSSA International Annual Meetings, Tampa, FL

Progress 04/15/16 to 09/30/16

Outputs
Target Audience:Growers in the southern High Plains of New Mexico wishing to adopt conservation practices for improvingsustainability of dryland and limited-irrigated productionsystems are the target audience. Similarly, this research will support activities of USDA Natural Resources Conservation Services andSoil and Water Conservation Society. Dryland producers across the world facing soil and water management challenges as in southern High Plains will be the secondary beneficiaries. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Three graduate students are being trained under this program. Area farmers were also trained by organizing field days, presentation at local meetings, and extension publications. Mr. Binod Ghimire, M.S. New Mexico State University, Las Cruces, NM. "Cover crops effects on soil properties, weed suppression, and wheat yields." Mr. Vesh B. Thapa, M.S. New Mexico State University, Las Cruces, NM. "Tillage and cover crops effects on corn-sorghum rotation." Ms. Mikayla Allan, M.S. New Mexico State University, Las Cruces, NM. "Residue input and SOM quality". How have the results been disseminated to communities of interest?Agriculture Science Center, Clovis organizes field day every year and attracts more than 120 farmers, and local stakeholders during this event. Results of the cover crops study was presented during the field day. Besides, special cover crops/canola field day was organized to help producers interested in adopting these practices. We also work closely with local USDA- NRCS, and Soil and Water Conservation District. The research outcome have been passed along to the producers and policy makers through their channels. We presented posters and also gave talks in Western Society of Crop Science, ASA/CSSA/SSSA Annual Meetings, University Council Research Fair, and 8th Curry County Prairie partner meeting. What do you plan to do during the next reporting period to accomplish the goals?This is the first year of the project. The research has been designed to continue for at least five to six years on the same field. Ongoing projects will be continued and the new projects will be initiated to address project goals and objectives. Extension materials will be developed for educating area farmers on cover cropping, crop diversification, and conservation tillage strategies. Completed data will analyzed and results interpreted for presentation in local meetings, field days, professional meetings and published as a journal paper or extension article. Existing and new graduate students will be trained. We will also continue strengthening the lab and field research works.

Impacts
What was accomplished under these goals? Alternative cropping systems that reduce or eliminate tillage and use improved crop, soil, and water management strategies were evaluated at the Agricultural Science Center, Clovis. Winter wheat was planted in October 2015, cover crops and mixtures were planted in February 2016. Cover crops growth, weed population, soil surface temperature, soil water, soil organic matter, and available nitrogen and phosphorus contents are monitored periodically.Early results of the study revealed that cover crops used soil moisture and available nutrients, added plant biomass, and improved soil microbial activity. The nutrient utilized by the cover crops is expected to be released during the following crop season.Another experiment has been established for comparing tillage systems in a corn-sorghum rotation and crop yields, profitability, and soil quality are monitored every year. Early response of alternative tillage systems revealed that reduced-tillage management has improved agroecosystem performance through their effects on soil organic matter dynamics. Besides existing research on cover crops and conservation tillage practices, we are synthesizing literature and evaluating opportunities and challenges of integrating cover crops in dryland and limited irrigation cropping systems.

Publications

• Type: Journal Articles Status: Published Year Published: 2016 Citation: Ghimire R. 2016. Approaches in Cropping Systems Research and Challenges (Invited Opinion). Advances in Plant and Agricultural Research. 3(2): 00088. DOI: 10.15406/ apar.2016.02.00088
• Type: Journal Articles Status: Under Review Year Published: 2017 Citation: Ghimire, R., B. Ghimire, A.O. Mesbah, M. ONeill, J. Idowu, S. Angadi, and M.K. Shukla. Cover crops for improving soil quality, weed suppression, and sustainable crop production in the southern High Plains, USA- A Review. Manuscript in review (Jan. 26, 2016).
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: Ghimire R., S. Angadi, S. Begna, M. Marsalis. 2016. Alternative strategies for improving sustainability of dryland and limited-irrigated cropping systems in eastern New Mexico. Ogallala Water CAP, first annual meeting, Denver, CO.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Duval, B.D., R. Ghimire, M.D. Hartman, M. Marsalis. 2016. Biogeochemical responses of a semi-arid sorghum system to management intensity and simulated future climate. AGU fall meeting. San Francisco, CA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Ghimire, R., A.O. Mesbah, B. Ghimire. 2016. Nutrient dynamics under cover crops and the following winter wheat and sorghum. ASA, CSSA, SSSA International Annual Meetings, Phoenix, AZ.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: 7. Ghimire, R., J. Szaloy, B. Ghimire, and A.O. Mesbah. 2016. Cover crops in a winter wheat-sorghum-fallow system: first year results of the soil properties and water use. Western Society of Crop Science Meeting, Albuquerque, NM.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Ghimire, B., R. Ghimire, A.O. Mesbah, J. Szaloy. 2016. Potentially mineralizable carbon under cover crops: results of a field and laboratory incubation study. Western Society of Crop Science Meeting, Albuquerque, NM.