The Big Global Research Issues and Implications for Australia

Transcription

1 The Big Global Research Issues and Implications for Australia Rob Norton, Regional Director, Australia & New Zealand, International Plant Nutrition Institute, ( Abstract Undoubtedly, given the vagaries of climate and the increasing world population, food security, food quality and environmental integrity are key issues facing humanity. The global research community has several initiatives to seek solutions to producing enough nutritious food for 9 billion people from a limited landbase. For example, biofortification of Zn and Fe levels in grains, part of the Harvest Plus Challenge, directly links nutrient management to human nutrition. IPNI maintains that fertilizer best management practices (BMP s) combined with sound agronomy are necessary to produce more food and this can be done while protecting our precious natural resources, including phosphorus. Introduction There is only one major issue facing the global community and that is framing a reasoned and science based response to the challenge of nurturing 9 billion people using the current land resource. Over the next 40 years, there is a global challenge to provide adequate, nutritious, safe and accessible food to all. This is a significant challenge given the other issues facing agriculture and land use across the globe. Food Nutritional Value It has been estimated that there are 450,000 deaths of children under 5 due to zinc (Zn) deficiency. This is particularly a problem in less developed countries where a grain based diet is the staple. Fruits, vegetables, and animal products are rich in micronutrients, but these foods are often not available to the poor. Their daily diet consists mostly of a few inexpensive staple foods, such as wheat, rice or cassava maize all have relatively low micronutrient levels, including Zn. To address this problem (along with low iron and low Vitamin A levels) the Harvest Plus Global Challenge was established in 2002 drawing on the resources of the international research community ( An IPNI grain nutrient level survey undertaken in 2009 found that Australian grain averaged 23±7 mg/kg of Zn, while the mean from Indian, USA, Canada and Chinese samples was 31±12. Grain from the Mallee and Eyre Pennisula was lowest with an average of 19 mg/kg. Based on the human nutritional demands, Harvest Plus has set a target of ~35 mg/kg. Breeding zinc efficient crops and applying fertilizer Zn are both effective at raising grain Zn levels, but for Australian growers, it is much easier to raise Zn levels than it is to achieve grain yield increase with Zinc fertilizers. Food Supply Security Based on 2010 USDA figures, grain production forecast for the 2010/11 crop season indicates that wheat supply will again fall below wheat production, with carry forward wheat stocks at 26% of consumption. Australia is only a small player, producing around 4% of global production but does contribute around 13% of the worlds traded wheat, which is enough to feed around 60 million people annually. In terms of food security, wheat and coarse grain is somewhat worse that just for wheat with stocks at 20% of consumption. Pre 2000 stocks were never less than 22% of consumption but since 2000, stocks have fallen to less that 20% in 5 of 10 years. Australian Fertilizer Industry Conference, August 23 26,

2 The implications of this for Australia is that market fundamentals would suggest that with good seasons beckoning, profitability will return to grain producers, especially in south eastern Australia where yield potentials are holding up with good rains. In the longer term, with a doubling of food demand by 2050, the market for Australian produce seems sound. Growers have been able to continue to improve grain yields, without recourse to expanding production areas. Cassman termed this trend of high productivity as ecological intensification and this has delivered increasing food supply as well as preserving land for wildlife and non agricultural pursuits. To continue with even half the productivity trends seen over the past 30 years should see production increase in Australia to 45 Mt, of which 30 Mt is wheat. However, to support this production, nutrient inputs would need to increase to match the losses typical in an open agricultural ecosystem. Nutrient Balances Vitousek et al. (2009) estimated nutrient balances for some agroecosystems, and noted that balances of N and P varied widely with, for example the Midwest of USA having a positive N balance (+10 kg/ha/y) and a negative P balance ( 9 kg P/ha/y). Australian data is sadly lacking with the last comprehensive assessment of nutrient balanced published in 2001, based on data collected in the 1990 s (Table 1). Table 1 Apparent nutrient balances for Australian states (ANRA Audit, 2001) for N, P, K and S. WA SA Vic Tas NSW Qld N +/~ ~/ + ~/+ ~/ P ~/+ ~ /~ + ~/ K ~ S +/~ ~/+ ~/+ + ~/+ /~ Despite this overview, at a paddock, farm or catchment level, the high degree of spatial and temporal variability can mask situations where either surplus nutrients are being applied possibly causing nutrient pollution on site or off site, or insufficient nutrient is being applied so that soil fertility is reduced. Getting to at least a nutrient balance should be the key target for nutrient management and there are tools available such as Lime and Nutrient Balance (John Angus and Keith Helyar see GRDC Lime and Nutrient Balance v1.2) for the grains industry or Overseer Nutrient Budget Program developed in New Zealand. NuGIS For the last couple of years, IPNI has been working on a rigorous GIS based model for assessing nutrient balance and balance trends in the U.S.A., termed NuGIS. This project is part of IPNI s responsibility for understanding the nutrient status of cropping systems and as a complement to our periodic inventorying of soil fertility levels in the U.S.A. By integrating multiple data layers to create county level estimates of nutrient removal by crops, fertilizer applied, and manure nutrients, NuGIS offers a rather clear picture of normal nutrient use. Geospatial techniques are used to migrate the county data to watersheds which will allow NuGIS output to be compared to the output of water quality models. Australian Fertilizer Industry Conference, August 23 26,

3 NuGIS is available as an IPNI Technical Bulletin in printed form that can be accessed at the IPNI website ( As of August 2010, there is the capacity to access the balance data interactively via an on line tool that allows panning from the entire country down to a few counties or watersheds. IPNI will also be preparing additional more focused publications on the findings of this project in the months ahead. While focused on the US at present, there are plans to develop NuGIS for datasets from India, Canada and Brazil, as well as possibly Australia if appropriate nutrient supply data sets can be accessed. Nutrient Management Best Management Practices Best Management Practices (BMPs) can be aptly described as the application of the right source (or product) at the right rate, right time and right place. Under the Global 4R Nutrient Stewardship Framework, the four rights (4R) comprehensively convey how fertilizer applications can be managed to achieve economic, social and environmental goals. The framework ensures that FBMPs are developed with consideration of the appropriate focus on all three areas of sustainable development (see Figure 1). Figure 1: The 4R s approach to nutrient best management practice, to meet environmental, economic and social demands. A full description of the logic and background to the 4R s approach is given in Bruulsema et al, (2009) a copy of which is appended to this paper. This approach is now the cornerstone for developing nutrient management BMP s and the first two produced in this format for Australia will be released in the next month from the IPNI website ( Global Fertilizer Issues and Expected Role of Fertilizer BMPs Many issues challenge the fertilizer and agricultural industries around the world. The following lists the some of the major issues that are global in scope, and briefly describes the role of BMPs in addressing the challenges imposed. Fertilizer use BMPs are relevant in some degree to almost every issue. However, complete solutions to some issues may go beyond their scope. 1) Nutrients in the Environment a) Eutrophication and hypoxia minimize losses of N and P in water. b) Ammonia emission and air quality minimize loss of ammonia in airsheds contributing to populated and industrialized areas. c) Nitrous oxide emission and stratospheric ozone minimize loss as nitrous oxide through increases in N use efficiency and management of soil water. Australian Fertilizer Industry Conference, August 23 26,

4 d) Nitrate in drinking water minimize surplus N accumulation in well drained soils. e) Biodiversity no direct role, but a combination of BMPs that increase both N use efficiency and maintain high yields would protect ecological diversity on a large scale. 2) Global Climate Change a) Nitrous oxide emission minimize loss as nitrous oxide through increases in N use efficiency and management of soil water. b) GWP of fertilizer manufacture and transport choice of fertilizer source. c) Rising CO 2 impact on crop nutrient demand choice of fertilizer source (ammonium versus nitrate). d) Climate influence of crop nutrient demand right rate for changing yield potentials. e) Fertilizer influence on soil C storage optimize growth of full crop rotation including cover crops. 3) Sustainability of Cropping Systems a) Soil organic matter levels and structural stability optimize growth of full crop rotation including cover crops; minimize soil compaction, organic manure application, straw return. b) Trace elements in fertilizers (e.g. Cd in phosphate fertilizers and organic biosolid wastes) choice of source for selected Cd accumulating crops in high Cd soils. c) Limits to nutrient recycling appropriate regulation of biosolids applications. d) Non renewable resources for fertilizer production optimize nutrient use efficiency. e) Fertilizer influence on plant pests and diseases optimize plant nutrition for suppression of disease. 4) Profitability and Productivity of Cropping Systems a) Rising cost of fertilizers optimize nutrient use efficiency through right source, rate, timing and placement. b) Price and value of crop commodities manage nutrition to optimize quality. c) Inconsistent of soil nutrient supply and crop demand Assess dynamics of soil nutrient supply and crop demand in different growing stages to optimize rate and time of nutrient application. d) Opportunities for value added production manage nutrition to optimize the level of trace elements and other quality parameters including phytochemical and nutraceutical components. e) Genetic yield potential of crops adaptation of right source, rate, timing and placement to changing growth traits of newly developed cultivars. f) Imbalanced use of nutrients required by crops balanced use of macro, micro and secondary nutrients through site specific adaptation of fertilizer use BMPs. g) Nutrient management in different crop rotation system considering allocation of nutrients in various crops in specific cropping system such as wheat corn, rice rice or rice wheat system. 5) Public Perception of Fertilizer a) Stigma arising from regulation encourage recognition of fertilizer use BMPs within the development of regulations and protocols. b) Nutrient management plans encourage flexibility in site specific adaptation of fertilizer use BMPs, meeting the criteria of simultaneously enhancing profitability, productivity, sustainability and environmental health. c) Fertilizer nutrients and organic food production choice of right fertilizer sources and organic nutrient management including straw return and animal manure application. 6) Integration of nutrient management and other agronomic practices a) Water management encourage recognition of interaction of nutrient and water management regime, especially in arid and semiarid regions or lowland rice system. b) Tillage system right source, rate, place and time of nutrient application in reduced or none tillage system. c) Crop cultivation adaptation of right source, rate, timing and placement to changes of planting density and method. Australian Fertilizer Industry Conference, August 23 26,

5 Earn 1 CEU in Nutrient Management Editor s note: This is the first article in a five-part series from the International Plant Nutrition Institute titled Know Your Fertilizer Rights, sponsored by The Fertilizer Institute and the Canadian Fertilizer Institute. The series is based on fertilizer best management practices structured around the 4R nutrient stewardship concept. For more information, visit Know your fertilizer rights By Tom Bruulsema, International Plant Nutrition Institute, Guelph, ON, Canada; Jerry Lemunyon, USDA- NRCS, Fort Worth, TX; and Bill Herz, The Fertilizer Institute, Washington, DC his article describes a new, innovative approach T to best management practices (BMPs) for fertilizer known as 4R nutrient stewardship. It ensures that the right source (or product) is applied at the right rate, right time, and right place. This simple concept can help farmers and the public understand how the right management practices for fertilizer contribute to sustainability for agriculture. Getting practices right depends on important roles played by many partners including farmers, crop advisers, scientists, policymakers, consumers, and the general public. Sustainability The increasing number and importance of issues surrounding the management of crop nutrients makes it necessary to have an approach that clearly describes the practices and their impacts. On the one hand, nutrient applications increase yields of crops, nourishing the world while sparing land for other uses and increasing the return of organic carbon to the soil, thereby sequestering a greenhouse gas. On the other hand, unmanaged nutrient applications may increase nutrient losses, potentially degrading water and air quality in a number of ways and possibly increasing greenhouse gases. Fertilizer use also has longer-term and larger-scale impacts on soil productivity and the social and u The 4R nutrient stewardship concept defines the right source, rate, time, and place for fertilizer application as those producing the economic, social, and environmental outcomes desired by all stakeholders to the plant ecosystem. Continuing Education Self-Study Course Earn 1 CEU in Nutrient Management by reading this article and completing the quiz at the end. CCAs may earn 20 CEUs per two-year cycle as board-approved self-study articles. Fill out the attached questionnaire and mail it with a $20 check (or provide credit card information) to the American Society of Agronomy. Or, you can complete the quiz online at www. certifiedcropadviser.org ($15 charge). economic structure of rural areas. These issues are all part of sustainable development. The 4R nutrient stewardship concept is being developed because sustainable agricultural production is important, and we need to ensure that fertilizer use contributes to it. The fertilizer rights source, rate, time, and place are connected to the goals of sustainable development. Internationally, sustainable development is recognized to consist of three nonnegotiable elements: economic, social, and environmental. Progress in each of those three areas is essential to sustainability. How the progress will be achieved requires input from stakeholders. For fertilizer use to be sustainable, it must support cropping systems that provide economic, social, and environmental benefits. The connection between the practices and the benefits must be understood well, not only by crop producers and their advisers, but also by those who purchase the products of cropping systems and those who live in the environment impacted by those systems. Programs involving payments to farmers for ecological goods and services for example, carbon offsets related to greenhouse gas mitigation, loading reductions for water quality credit trading, etc. depend on a clear public understanding of these linkages and a common language and vocabulary relating to fertilizer management. Who decides what s right? Traditionally, a team of farmers, researchers, natural resource managers, extension staff, and agribusiness professionals or a subset of this team has decided what would qualify as a best management practice. Today there is still no doubt that the expertise of all these people is important to determining the right management on a practical basis. A sustainability-focused approach, however, is more u March April 2009 Crops & Soils 13

6 Continuing Education comprehensive and includes input from all stakeholders in determining the indicators, measures, benchmarks, and targets for performance of the management practices implemented. So what s right is determined by how these people want the cropping system to perform. Stakeholders of cropping systems include the people who consume its products and the people living in the environment it impacts. The perspectives of all of these stakeholders must be reflected in the economic, social, and environmental goals that are set for the cropping system. Fertilizer management, to be considered right, must support those goals. All stakeholders have input to the goals. However, the farmer the manager of the land is the final decision maker in selecting the practices suited to the local site-specific soil, weather, and crop production conditions that have the highest probability of meeting the goals. Because all these conditions can influence the decision on the practice selected, right up to and including the day of implementation, local decision making with the right decision support information performs better than a centralized regulatory approach. For example, a recent BMP guide for dairy-based cropping systems in the Northeast was developed using the input of farmers, agribusiness professionals, land grant university extension, and staff of the USDA-NRCS. Performance goals for farm profitability and off-farm impact on water quality were the foremost considerations of this body of experts, based on input from experience with environmental agencies, public interest groups, and policymakers. The BMP guide they developed listed 20 general practices under the categories of right source, rate, time, and place (Bruulsema and Ketterings, 2008). What does it mean to apply the right source at the right rate, right time, and right place? The phrase right source at the right rate, right time, and right place implies that each fertilizer management practice or group of practices is right i.e., effective in terms of the goals of sustainable production. It also implies that there are four aspects to every fertilizer application and provides a simple checklist to assess whether a given crop has been fertilized properly. Asking Was the crop given the right source at the right rate, time, and place? helps farmers and advisers to identify opportunities for improvement in fertilizing each specific crop in each specific field. A balance of effort among the four rights is appropriate. It helps avoid too much emphasis on one at the expense of overlooking the others. Rate may sometimes be overemphasized, owing to its direct relation to cost. Source, time, and place are more frequently overlooked and hold opportunity for improving performance. The phrase also clearly describes to the fertilizer industry that farmers have specific requirements for the delivery and distribution of the right nutrient forms suited to their application equipment in the right amounts to support the right Earn 1 CEU in Nutrient Management rate at the right time and to the right place. Meeting these logistical challenges is the fertilizer industry s role in delivery and distribution. Grouping specific practices associated with fertilizer management under the headings of source, rate, time, and place helps ensure that no critical steps in fertilizer management are overlooked. In that way, they are valuable to the farmer and the crop adviser. To ensure sound agronomy, the manager asks, Am I using every tool available to choose the right product, to predict its right rate, to apply it at the right time, and to place it where it s most effective for my crop, soil conditions, and weather? The four headings also help farmers, crop advisers, and agronomic scientists to clearly communicate with stakeholders less familiar with agriculture. Are the four rights independent or interconnected? The four aspects of fertilizer management source, rate, time, and place are completely interconnected and also linked to the full set of management practices for the cropping system. None of the four can be right when any one of them is wrong. It is possible that for a given situation, there is more than one right combination of source, rate, timing, or placement, but when one of the four changes, the others may as well. For example, it may be true for certain farms in a certain region that a single application of a controlledrelease source of nitrogen (N) is equal in costs and benefits to a split application of a soluble N source. The two sources would obviously differ in the right time of application. They would be equally right if they achieved the same performance from the cropping system at the same cost. However, in many practical situations, one combination may be preferred over another because of a better fit with the logistics of the operation or with the range of weather risks to which each might be susceptible. The four rights must work in synchrony with each other and with the surrounding plant-soil-climate and management environment. One change of step or direction may cause the entire system of nutrient management to fall short of its intended goal. The combination of source, rate, time, and place changes depending on the crop management system as well. For example, a broadcast fertilizer application incorporated before planting may suit a corn soybean rotation with tillage, but a band application and injection may be needed under no-till management. So the right source, rate, time, and place are interconnected, not independent, and are linked strongly to crop management and to local site-specific soil, weather, and climate conditions. What scientific principles apply? The sciences of physics, chemistry, and biology are fundamental to the mineral nutrition of plants growing in soils. 14 Crops & Soils March April 2009 American Society of Agronomy

7 Earn 1 CEU in Nutrient Management Continuing Education u Table 1. Key scientific principles used in developing practices for determining right source, rate, time, and place. Category Source Rate Time Place Examples of key scientific principles Ensure a balanced supply of essential nutrients, considering both naturally available sources and characteristics of specific products, in plant-available forms. Assess soil nutrient supply and plant demand. Assess dynamics of crop uptake, soil supply, and logistics of field operations. Determine timing of nutrient loss risks. Recognize root-soil dynamics. Manage spatial variability within the field to meet site-specific crop needs and to limit potential losses from the field. The application of these sciences to practical management of plant nutrition has led to the development of the scientific disciplines of soil fertility and plant nutrition. Each of the four management components of source, rate, time, and place has unique science describing fundamental processes. Science also studies and describes whole systems. Both levels of science are relevant because there are gaps in the knowledge of the fundamental processes and crop production systems or plant ecosystems are complex and can respond in unanticipated ways to the application of nutrients. So the science backing a particular practice needs to include both that which documents how the practice works at the basic level and that which measures the outcome in terms of changes in performance of the cropping system in which fertilizers are applied. Specific scientific principles guide the development of practices determining right source, rate, time, and place. A few of the key principles are shown in Table 1. These and other important principles of plant nutrition will be described in more detail in the next four articles in this series. The principles are the same globally, but how they are put into practice locally varies depending on specific soil, crop, economic, climate, and weather conditions. Agronomists and crop advisers make sure the practices they select and apply locally are in accord with these principles. What is performance and how is it assessed in implementing the four R s? Performance is the outcome of implementing a practice. The impacts of fertilizer management are expressed in the performance of the cropping systems or soil plant air ecosystems in which they are applied. Performance includes the increase in yield, quality, and profit resulting from a fertilizer application and extends to long-term effects on soil fertility levels and on losses of nutrients to water and air. It also includes impacts on the regional economy and social conditions for example, affordable food. Not all aspects of performance can be measured on each farm, but all should be assessed. Planning indexes and computer models may be used for these assessments but need to be acceptable to stakeholders. Performance is assessed through measures and indicators. It relates to all outcomes considered important to stakeholders (farmers, agribusiness, consumers, and the general public). Performance measures are detailed measurements of the actual outcome of the implementation of a particular management practice to a particular cropping system. They can be very expensive and difficult to do. Performance measurements are done primarily by research agronomists and are used to validate management practices, often in a controlled field context designed to extrapolate to a large number of practical farm crop situations. An example may be a field trial on an experiment station in which two or more practices are compared and where measurements include crop yields, nutrient uptake, losses of ammonia and nitrous oxide to the air, losses of nutrients in runoff and drainage water, etc. The 4R concept helps guide research and extension toward validation of practices most relevant to achieving the economic, social, and environmental outcomes that stakeholders consider important. Performance indicators are simpler measures that can be done on actual farms. Stakeholders need to agree that they reflect their aspirations for performance and that the indicators correlate well to actual measurements. For example, where soil erosion is a major issue and a large source of nutrient loss, an indicator measuring crop residues covering the soil at critical times may be suitable. Since fertilizer applications have multiple impacts, no single measure or indicator provides a complete reflection of performance. Neither can all possible impacts be measured. Stakeholders need to select the performance measures and indicators that relate to the issues of greatest concern. A partial list of indicators from which they can select follows in Table 2. It is important to recognize that none of these is affected by fertilizer management alone. All can be improved by applying 4R nutrient stewardship, but they also depend on sound management of all practices applied to the cropping system or plant ecosystem. For instance, a good fertilizer program for turfgrass will not assure erosion control if clipping management, or species selection, is inappropriate. u March April 2009 Crops & Soils 15

8 Continuing Education Which are the most important performance indicators? Crop managers or crop advisers cannot select the most important performance indicator on their own. Stakeholder input is required to select performance indicators representing progress on the goals considered important by all. It is often assumed that nutrient use efficiency is the most important indicator of performance for fertilizer use. This is not the case. Fertilizers are applied to increase the overall performance of the cropping system. Nutrient use efficiency is only one aspect of that performance, as indicated in Table 2. Nutrient use efficiency has many definitions, reflecting nutrient recovery, nutrient balance, or yield in relation to nutrients applied. Each provides unique indications of potential for improvement of fertilizer management, but Earn 1 CEU in Nutrient Management none provides a full representation of the impact on overall performance. In a nutshell, the 4R stewardship concept involves crop producers and their advisers selecting the right source rate time place combination from practices validated by research conducted by agronomic scientists. Goals for economic, environmental, and social progress are set by and are reflected in performance indicators chosen by the stakeholders to crop production systems. X Reference Bruulsema, T.W., and Q.M. Ketterings Best management practices for fertilizers on Northeastern dairy farms. Fertilize BMP Item ; Ref International Plant Nutrition Institute, Norcross, GA. u Table 2. Performance measures and indicators for fertilizer management practices. Performance measure or indicator Yield Quality Nutrient use efficiency Water use efficiency Labor use efficiency Energy use efficiency Net profit Return on investment Adoption Soil productivity Yield stability Farm income Working conditions Water and air quality Ecosystem services Biodiversity Soil erosion Off-field nutrient losses Nutrient budget Description Amount of crop harvested per unit of cropland per unit of time. Sugar, protein, minerals, vitamins or other attributes that add value to the harvested product. Yield produced or nutrient taken up per unit of nutrient applied. Yield per unit of water applied or available. Labor productivity, linked to number and timing of field operations. Crop yield per unit of energy input. Volume and value of crop produced relative to all costs of production. Profit in relation to capital investment. Proportion of producers using particular BMPs. Soil fertility levels, soil organic matter, and other soil quality indicators. Resilience of crop yields to variations in weather and pests. Improvements in livelihood. Quality-of-life issues, worker satisfaction, employee turnover. Nutrient concentration and loading in watersheds or airsheds. Countryside aesthetics, natural predators and pollinators, outdoor recreation, hunting, fishing, etc. Difficult to quantify can be descriptive. Degree of soil coverage by actively growing crops and crop residues. The combined total of nutrient losses from the agricultural management zone edge of field, bottom of root zone, and top of crop canopy. A total account of nutrient inputs and outputs, at the soil surface or farm gate. The relative importance among these and other indicators needs to be determined by stakeholder input. 16 Crops & Soils March April 2009 American Society of Agronomy