Kerala faces an economic situation that encourages farmers to adopt practices that exacerbate climate change and biodiversity loss, erodes coffee quality, and undermines farmer’s livelihoods. In the biodiversity hotspot of Wayanad, Kerala, weather is getting hotter and drier, particularly during months when precipitation is vital to the life cycle of the coffee plant. These trends compound the existing threats faced by farmers and biodiversity in the region. Personal experience of farmers in Wayanad was corroborated by quantitative analysis. Researchers studying agricultural systems should engage with local constituents to guide research efforts, particularly in regions where tribes have yet to be disenfranchised and ancient knowledge is still intact. Reforestation, reinstatement of traditional intercropping methods, and regeneration of healthy soils are likely to be the most effective strategies for both climate and economic resilience. Price stabilizing mechanisms such as a guaranteed floor price should be reinstated, as they were in the past, to protect farmers against multinational vested interests. Policies that incentivize carbon sequestration and reforestation should be implemented in order to mitigate and adapt to climate change, and to provide better livelihoods for the people that grow crop commodities. Consumers should be engaged and educated on these issues in order to shift market forces towards business practices that support these efforts. Readers of all affiliations should consider the global impacts of their daily choices as consumers, strive towards lifestyles that eliminate frivolous use of resources and promote ethical economies,commercial greenhouse supplies and participate in the world in a responsible way for the sake of all life on Earth, including present and future generations.
Agricultural productivity in the United States has increased dramatically over the last few decades, but in the face of climate change current management practices might not sustain current levels of production . Some practices that achieve high crop yields and profit — for example, minimal use of crop rotations, high rates of fertilizer and pesticide inputs, minimal carbon inputs and soil disturbance — also result in degradation of ecosystem processes on which agricultural systems rely. Such degradation can reduce resilience, making these systems more vulnerable to high temperatures and uncertainty in water supply, resulting in lower productivity in times of extreme weather conditions, such as prolonged drought . Climate-smart agriculture means increasing resiliency to extreme and unpredictable weather patterns induced by climate change by following three principles: developing agricultural cropping systems that are productively resilient in the face of climate change; reducing greenhouse gas emissions attributable to agriculture to further reduce contributions to global warming; and proactively and adaptively managing farms in a way to buffer farm productivity and profitability against the negative effects of climate change. To make informed, evidence-based management decisions under new climate change regimes, data is needed from long-term agricultural experiments, few of which exist. As weather and climate patterns change, repeated measurements over decades can reveal what may be slow but incremental changes in crop yield and quality, as well as soil quality and biodiversity . A long-term agricultural experiment, known as the Century Experiment, is underway at the Russell Ranch Sustainable Agriculture Facility , a unit of the Agricultural Sustainability Institute at UC Davis. RRSAF is a 285-acre research facility and working farm where, under realistic commercial scale conditions, controlled long-term experiments are testing a variety of crop systems and management practices related to fertility and nutrient management, irrigation and water use, energy use, greenhouse gases and soil health.
The Century Experiment was designed as a 100- year replicated experiment. It was initiated in 1992, when environmental and soil conditions were monitored as a baseline prior to installation in 1993 of 10 cropping systems across 72 one-acre plots; since then, one additional cropping system and restored native grassland reference plots have been introduced . Soil and plant samples are collected regularly and analyzed, and sub-sampled for archive and future analysis.Energy use, inputs and outputs are monitored for all equipment and groundwater pumping throughout the year. The interior of each 1-acre plot in the Century Experiment is maintained consistently for collection of the long-term dataset. Microplots and strips within each plot are available for additional experimental investigations, which have included the impacts of different fertilizers or crop varieties, pest management practices, tillage practices and soil amendments. RRSAF research is also conducted in additional plots that are not part of the Century Experiment to focus on questions that explore practices that may ultimately be adopted within the main experiment. This research includes targeted investigations of soil amendments, irrigation frequency and type, and new crop varieties, and it permits side-by-side comparisons of management history on the effectiveness of different practices. UC and UC Agriculture and Natural Resources researchers and the RRSAF team collaborate regularly with local growers, as well as with researchers from other institutions throughout the United States and around the world, so that the research addresses local issues and also has broader relevance for agriculture in Mediterranean climates worldwide. Maintaining healthy soils is a key to climate-smart agriculture. Properties such as porosity, water retention, drainage capacity, carbon sequestration, organic matter content and biodiversity all help to confer resilience to new pest and disease pressures and to extremes in temperature and water availability .
The California Department of Food and Agriculture’s Healthy Soils Initiative, launched in 2016, reflects the state’s commitment to improve the quality of managed soils . Encouraging best practices for maintaining healthy soils will increase biodiversity as well as beneficial physical and chemical properties of soil. Improving these properties will, in turn, confer resilience of agro-ecosystems to uncertainties in climate, including unpredictable rainfall patterns, new extremes in temperature and unexpected shifts in the distribution of pests and diseases . Intensive soil sampling is a key part of the Century Experiment. Plots are sampled at least once every 10 years to as deep as 3 meters in eight depth intervals, and a number of chemical and physical properties are measured. After 20 years, cropping systems, with few exceptions , either maintained or increased total soil carbon content to a depth of 2 meters . Soil carbon increased significantly more in the organic tomato-corn system than it did in any other crops and management systems. Soil infiltration rates and aggregate stability were also greater in the organic than conventional tomato corn system. This research also identified specific soil fractions where early changes in carbon sequestration can be detected, to help predict which practices promote increases or decreases in soil carbon. Changes in soil biology were evident as well: microbial biomass was 40% higher in soils in organic than in conventional tomato-corn rotations, and microbial community composition under organic and conventional management was distinctly different. More indepth analyses of the soil biota, including sequencing of soil microbial communities and measuring abundance of mycorrhizal fungi, are underway.Use of agricultural and food wastes, and cover crops, can reduce dependency on synthetic fertilizers that rely on fossil fuels and generate greenhouse gases in their synthesis. Also, use of soil organic amendments helps organic and conventional growers to “close the loop” by reducing energy and environmental costs of waste disposal,vertical grow and recycling valuable nutrients back into the soil. At RRSAF, composted poultry manure and winter cover crops provide sufficient nitrogen and other nutrients to the organic tomato-corn rotation. Organic tomato yields for 20 years under furrow irrigation were not significantly different from conventional tomato yields. Soil amendments and winter cover crops have led to increased soil carbon sequestration, higher infiltration rates and greater aggregate stability in the organic system compared to the conventional systems; however, these benefits may be of limited interest to growers if yields are substantially reduced. A challenge is how to combine use of organic inputs with subsurface drip irrigation for organic systems. Organic relies on solid sources of fertility, for example, cover crops and compost, that cannot be delivered in the drip line, and that rely on microbial activity to convert them into plant-available forms. In SSDI systems, only a limited area of the bed is wetted and microbial activity may be reduced. Researchers at RRSAF are investigating the feasibility of using different combinations and forms of solid and liquid organic amendments in organic tomato-corn rotations. This is particularly timely as interest in organic farming and products increases . In 2012, a long-term experiment was initiated with the soil amendment biochar, a form of charcoal made from pyrolysis of organic waste materials. Application of biochar to tomato-corn rotations at 10 tons per hectare resulted in corn yields increasing in year 2 by approximately 8%, but no other yield effects were observed over 4 years .
Biochar had no impact, however, on soil water retention. These results underscore the importance of being able to draw conclusions based on long-term research, and the experiment continues to be monitored. Water quantity and quality are critical concerns for climate-smart agriculture in chronically drought-afflicted California . SSDI may increase crop yields, reduce weed pressure and improve water management in conventionally managed systems , but the trade-offs associated with other impacts of SSDI, such as changes to soil moisture patterns, reduced microbial activity, altered accumulation of salts and reduced groundwater recharge, have received little attention. At RRSAF, researchers are comparing effects of furrow versus drip irrigation on crop yields, root growth, microbial communities and soil structure. Many changes, such as soil aggregate structure, are not evident immediately and require long-term experiments to understand and resolve. Irrigation scheduling is another focus of water management at RRSAF. Different methods and associated technologies have been compared for estimating irrigation needs, including methods based on evapotranspiration , soil moisture sensors, plant water status and remote-sensing data. In tomatoes, an ET-based method was found to better predict crop water needs than soil sensor–based methods. Research projects at RRSAF have also addressed other aspects of climate-smart agriculture. These include development of farm equipment that reduces soil disturbance and energy consumption; application of sensor technology in collaboration with NASA’s Jet Propulsion Laboratory to support data-driven management choices in response to climate variation; and comparison of the efficacy of smart water meters in groundwater wells and irrigation systems. Other investigations have measured the feasibility of using dairy and food waste bio-digestate that can help offset consumption of fossil-fuel based fertilizers; tracking changes in wheat cellulose via isotopic methods to monitor plant responses to climate change; and measuring lower greenhouse gas emissions under SSDI than furrow irrigation. New varieties of climate-smart crops, such as perennial wheat, are being evaluated for their yield and resilience in California’s Mediterranean climate. In its 20 years, the Century Experiment has demonstrated a unique value in generating climate-smart data — for example, which practices enhance carbon sequestration in California row crop soils, how irrigation can be managed to reduce greenhouse gas emissions, and what sensors help most in reducing water consumption. Future research will address how soil biodiversity, such as the symbiotic mycorrhizal fungi, can be harnessed to reduce water and nutrient inputs, and increase crop resilience. Researchers exploring mechanisms driving short- and long-term responses to global change can guide the development of decision support models that incorporate economic, agronomic, ecological and social trade-offs and provide support for decision-makers — growers, policymakers, researchers — to make management decisions in the face of increasing climate uncertainty. The American Agricultural Economic Association is composed of various groups ranging from industry to government to academia with widely divergent values and interests. This has lead to controversy, sometimes healthy and other times destructive, on the appropriate mode for graduate training and methodologies of research. These differences affect the direction and vitality of the profession and imply both benefits and costs in pursuing the solutions to various problems and issues. Pressures.for day-ta-day decision making in industry have led to reliance on methodologies that are often characterized as unacceptable for journal publication. Similarly, the timeliness of analyses in governmental policy-making processes sometimes does not lend itself well to publication in professional journals. In contrast, the research sophistication that has emerged in academic circles has reputedly widened the divergences among various groups within the AAEA. In this setting a number of personalized views have been expressed.