Entire Farm Research Articles

Influences of soil, terrain, and crop growth on soil moisture variation from transect to farm scales

Soil and topography are widely recognized as important controls of soil moisture variation. Soil moisture distribution in a landscape has often been conceptualized as being controlled predominantly by soil properties during dry periods, and by topography during wet periods. However, this conceptualization does not explicitly consider plant growth, spatial scale, and soil depth. We investigated the influences of soil, terrain, and crop on soil moisture variation in an agricultural landscape at four spatial scales (entire farm of 19.5 ha, landform unit of 0.3–5.1 ha, plot size of 10 × 10 m, and slope transect of 40 × 2 m), in three depths (0.1, 0.4, and 0.8 m), and during two seasons (crop growing vs. non-growing seasons). The results showed that the controls on soil moisture variability varied by season, soil depth, and the degree of soil-topography variability at a given spatial scale. During the growing season, crop and soil exerted significant influences on soil moisture, especially at the 0.1- and 0.4-m depth; whereas during the non-growing season, terrain attributes showed more significant impacts on soil moisture variation, particularly at the 0.8-m depth where soils were generally wetter. In areas of steeper slope (> 8%), topography dominated over soil properties in controlling soil moisture variation, while in relatively flat areas (< 8% slope), soil properties dominated regardless of season and soil wetness. Generally, topographic influence on soil moisture increased with topographic variation (slope percent in this study). In hillslope with a greater variation in soil properties, soil's influence on moisture variation was apparent, but not in transects with relative homogenous soil properties. Overall, this study demonstrated the intertwined spatial complexity and temporal dynamics in soil moisture controls by terrain, soil, and crop across a typical agricultural landscape, the degree of which is a function of spatial scale, soil depth, and season.

Whole farm implications on the application of variable rate technology to every cropped field

In the last 10 years precision agriculture has evolved and it is now possible to manage cropping inputs at the sub field scale. However, the expected return generated by these management practices varies with the amount and predictability of the spatial variation in crop yield across the field and may vary from field to field across the farm. We analysed the spatial variation of crop yield from 20 fields totalling 2832 ha from a 5200 ha farm in Western Australia at the field and the sub field scale to determine the economic value of introducing variable rate management (VRT) strategies to fields across the entire farm. In this case study, 6 out of 20 fields generated an additional economic payoff of AU$15/ha when managed with VRT over uniform management. Sensitivity analysis found that the starting levels of soil fertility were an important driver of the payoff for managing a field with VRT. If starting soil fertility was low and uniform across the field, then no fields generated an economic return of more than AU$7.00/ha when managed with VRT. Other factors, including commodity price, fertiliser price, amount of variation in crop yield within the field moderately increased the value of adopting VRT across fields within farm the value of VRT increased if fertiliser budgets were constrained, particularly if the yield distribution of the field was negatively skewed. While VRT does add value to many fields across the farm, the gains are small and the technology must be implemented cheaply for it to be viable.

Capital Usage in Adverse Situations: Applying Bourdieu’s Theory of Capital to Family Farm Businesses

The paper applies Pierre Bourdieu’s theory of capital to explore how farming family businesses respond to critical changes by using different forms of capital. The paper tells the story of three cases from the United Kingdom (UK): case one lost the entire farm business in the 2001 Foot and Mouth Disease (FMD) crisis; case two the family had to overcome the sudden death of the farmer; and in case three the farmer was diagnosed with a terminal illness. The results indicate that levels of economic capital are adversely affected, whilst social and symbolic capitals are important in assisting family members to cope and continue the business operations. The paper raises questions for future research and provides interesting findings for those involved with family business.

Regional impacts of abolishing direct payments: An integrated analysis in four European regions

The direct payment system of the Common Agricultural Policy (CAP) provides income transfers to European farmers. Recently, several countries including England and Sweden have advocated the elimination of direct payments after 2013. The extent to which an elimination of direct payments would affect the land use dynamics in Europe including impacts on structural change and the environment has not been addressed in the existing literature. In this paper, we combine participatory methods, to analyze regional preferences for functions and effects of agriculture, and farm-level modeling, to assess the impacts of such a policy change on farm structures and land use intensities in four European regions located in Germany, Denmark, Italy and Poland, each with different socio-economic and biophysical characteristics. In each region, the entire farm population consisting of different farm types with different production orientations and land management types was modeled under the presence and absence of direct payments using a combination of agent-based and bio-economic modeling. We found that the initial characteristics of the regions, such as the historical farm structure and regional site conditions, greatly influence the impact of direct support elimination and cause regionally different development trends. The results for the four regions were summarized in four specific storylines that emphasize how much the diversity of European regions matters for future policy decisions. An explicitly regional focus is, therefore, argued to be crucial to complement future policy analysis.

Self-Reported Lower Respiratory Symptoms and Exhaled Nitric Oxide in a WTC-Exposed Cohort

S (ACE) AEP Vol. 20, No. 9 September 2010: 691–724 710 RESULTS: Population prevalences were estimated from 7,137 interviews (54% response rate). Most (91%) farm operators had health insurance. In the previous 12 months, Latino operators were less likely to have health insurance or receive prescribed medications compared with white-nonLatino operators. In addition, Latino men had more difficulty obtaining medical care, and had fewer emergency room visits than white-non-Latino men. African American and Alaska Native men and women were less likely to have health insurance, and a greater number of Alaska Native men reported difficulty obtaining medical care compared with white operators of the same gender. Asian American men were less likely to have emergency room visits and fewer Asian American men and women reported hospital stays during the last 12 months. Prevalence for reporting worse general health compared to a year ago were similar across ethnic and racial groups. CONCLUSIONS: Health care access and utilization for ethnic and racial groups of farm operators vary. Studies that combine these social categories may overor underestimate access to care and healthcare use in the entire farm operator population. P54 THE COST-EFFECTIVENESS OF BASELINE MRI VERSUS CT IN PATIENTS WITH CLINICAL SYMPTOMS STRONGLY SUGGESTIVE OF STROKEdA DECISION ANALYSIS KR Burton, Department of Health Policy, Management & Evaluation, University of Toronto, Ontario, Canada PURPOSE: All patients with stroke symptoms should undergo a “baseline” magnetic resonance imaging (MRI) or computed tomography (CT) study; however, it remains unclear whether immediate CT or MRI scanning yields a difference in long-term outcomes or costs. METHODS: A Markov decision analysis model was used with a population of any patient eligible to receive thrombolytic therapy who presents on any time of day and any day of the week to a healthcare facility, with stroke symptoms. The interventions studied were CT or MRI scan at baseline. The outcomes measured were costs (adjusted to 2008 dollars), qualityadjusted life years (QALYs), and incremental costeffectiveness. RESULTS: Compared with CT, the MRI strategy has an incremental costeffectiveness ratio (ICER) of $4,765 per QALY gained. The MRI strategy gains more QALYs than the CT strategy and incurs lower incremental costs; therefore, the MRI strategy dominates the CT strategy. Over a wide range of variables, the ICERs of the MRI imaging strategy were less than $50,000 per QALY gained, except for the cost associated with strokerelated life-years lost. Varying the prevalence of acute ischemic stroke, the costs of MRI and CT scans and the sensitivity and specificity of CT and MRI had no effects on outcomes. CONCLUSION: The most cost-effective strategy for baseline imaging of stroke patients is MR imaging. Clinically significant benefits accrue from imaging patients with MRI at baseline. P55 BARRIERS TO HEALTH CARE AMONG PARENTS USING CHILDREN’S HEALTH INSURANCE PROGRAM P Valencia-Castro, A Stachnik, D Fuentes, G Gaitan, W Yang, J Smith-Gagen, School of Community Health Sciences, University of Nevada, Reno, NV PURPOSE: We evaluated parents’ perceived barriers to health care, when using the Nevada’s State Children’s Health Insurance Plan (Nevada CheckUp) in seeking health care for their children. METHODS: Using the Andersen-Newman Behavioral Model of Health Service Use, we identified barriers to health care from self-administered questionnaires, collected among a group of newly enrolled Nevada CheckUp beneficiaries, between November, 2008 and May, 2009. RESULTS: A 39-item questionnaire measuring parents’ barriers to obtaining health care for their children was completed by 356 Nevadan parents. Among them, 56.5% (n Z 201) had one child and 43.5% (n Z 155) had two or more children. The most common predisposing factors affecting a parent’ propensity to use health care were communication with physician (69.0%, nZ 238) and knowledge of the health care systems (54.6%, nZ 191), at the contextual and individual level respectively. Similarly, almost half of the respondents reported having frequent problems with meeting the needs of other family members (44.6%, nZ 153). In contrast, most respondents reported no problems with doctor visit transportation (79.9%, nZ 282) or with contacting the doctor’s office by phone (68.2%, nZ 240). CONCLUSION: Contextual and individual characteristics that could predispose insured individuals to not use health services are a common problem. These findings should guide future policy and public health interventions.

Gender roles in agricultural production in the Seychelles

This study examined the role of each member of the family in food production, investigated the type of farming activities the farm families are engaged in, gender specific roles, level of participation of the female gender, gender stereotypes and suggested the use of the information for policy advocacy and strengthening of agricultural service delivery in the Seychelles. Two investigative tools were used namely Focus GroupDiscussion (FGD) and Interview Schedule.Atotal of 100 farmers were interviewed. The study revealed that the farmers were mainly crop farmers. There were no gender specific roles or stereotypes. Men were more involved in all the food production activities except food processing. Other areas of high level women participation were marketing (81%), farm hygiene (76%), record keeping (42.9%)and purchasing of inputs(81%). Low level female participation was a result of attitudinal change, difficult agricultural land terrain, unfavorable government policy and unwholistic approach of agricultural extension services which focused on only the farmer instead of the entire farm family. To achieve sustainable food production in order to ensure food security, the extension services need a new orientation and better funding to enable it carry out its function. The government should make available cultivable lands for food production and encourage women to own their own farms by giving priority to them in land allocation.Keywords: Gender, role, production, stereotype

CFD in Wind Energy: The Virtual, Multiscale Wind Tunnel

Over the past two decades, computational fluid dynamics and particularly the finite volume method have been increasingly used to predict the performance of wind turbines within their environment. Increases in available computational power has led to the application of RANS-based models to more and more complex flow problems and permitted the use of LES-based models where previously not possible. The following article reviews the development of CFD as applied by the wind energy community from small to large scale: from the flow around 2D airfoils to the flow through an entire wind farm.

Using a whole farm model to determine the impacts of mating management on the profitability of pasture-based dairy farms

An approach to assessing likely impacts of altering reproductive performance on productivity and profitability in pasture-based dairy farms is described. The basis is the development of a whole farm model (WFM) that simulates the entire farm system and holistically links multiple physical performance factors to profitability. The WFM consists of a framework that links a mechanistic cow model, a pasture model, a crop model, management policies and climate. It simulates individual cows and paddocks, and runs on a day time-step. The WFM was upgraded to include reproductive modeling capability using reference tables and empirical equations describing published relationships between cow factors, physiology and mating management. It predicts reproductive status at any time point for individual cows within a modeled herd. The performance of six commercial pasture-based dairy farms was simulated for the period of 12 months beginning 1 June 2005 (05/06 year) to evaluate the accuracy of the model by comparison with actual outcomes. The model predicted most key performance indicators within an acceptable range of error (residual < 10% of observed). The evaluated WFM was then used for the six farms to estimate the profitability of changes in farm “set-up” (farm conditions at the start of the farming year on 1 June) and mating management from 05/06 to 06/07 year. Among the six farms simulated, the 4-week calving rate emerged as an important set-up factor influencing profitability, while reproductive performance during natural bull mating was identified as an area with the greatest opportunity for improvement. The WFM presents utility to explore alternative management strategies to predict likely outcomes to proposed changes to a pasture-based farm system.

Biological Control of Alfalfa Snout Beetle with a multi-species application of locally adapted persistent entomopathogenic nematodes: The first success

Alfalfa snout beetle (ASB), Otiorhynchus ligustici (L.), is a very severe pest of alfalfa, grown in areas of northern New York and southeastern Ontario, Canada, bordering Lake Ontario and the St. Lawrence River. ASB often kills out entire fields in a single year from larval root feeding when populations are high. This parthenogenetic insect was first reported in North America in 1896 in Oswego Co., NY, where it was introduced by the dumping of sailing ballast between 1848 and 1896. ASB was identified as an alfalfa pest when alfalfa was introduced into the area in the 1920's. With ASB adults and larvae spending all of their 2-year life cycle in close association with soil, a biological control strategy focused on the use of locally adapted persistent entomopathogenic nematodes (EPNs) appeared to be a logical research direction. Research was initiated in 1989 and these studies were conducted primarily on a single farm (the John Peck Farm, located in Great Bend, Jefferson Co., New York) that historically contained extremely high populations of ASB. In 2002, the Peck Farm experienced an unexpected and sudden collapse of the ASB infestation. Subsequent studies on the Peck Farm revealed that the combination of two locally adapted nematodes had dispersed throughout the entire Peck Farm. We believe that the coexistence and soil residence partitioning of H. bacteriophora 'Oswego' with the native S. carpocapsae 'NY001' together exposed a wider range of life stages of ASB to nematode attack and subsequently applied enough biological control pressure on snout beetle to reduce the population to sub-economic levels. This research suggests that using locally adapted EPNs in a multi-species application provides a more effective approach to the biological control of ASB and potentially that of other soil pests.

Farmer Assessment of the Certified Safe Farm Program

ABSTRACT This article summarizes the qualitative findings from a study evaluating a novel agricultural health and safety program called Certified Safe Farm (CSF). Results are presented from focus groups held in 2002 and 2006 as well as mail-out surveys conducted in 2001 and 2002. Focus group participants and survey responders were farmers involved in CSF intervention studies. CSF aims to remove hazards through on-farm safety reviews, detect health concerns through clinical screenings, provide personalized occupational health and wellness education, and provide incentives for meeting farm safety targets. Farmers overwhelmingly felt that CSF was beneficial for their health and safety by improving their knowledge and behaviors. In both the focus groups and questionnaires, farmers felt that occupational health screening was the most important component of CSF, and on-farm safety review was the second most important component. Farmers also helped to identify areas in which CSF could be improved in the future. Major areas of suggested program improvement included increased involvement of entire farm families, increased enrollment of younger farmers, increased program incentives such as reduced insurance premiums, and increased ease of access to program providers (AgriSafe clinics), among other recommendations.

A Swiss agri-environment scheme effectively enhances species richness for some taxa over time

The effectiveness of agri-environment schemes (AESs) in promoting biodiversity was recently debated. One reason for limited effectiveness of AESs may be their application to small and scattered patches of land. This study presents the evaluation of a scheme adopted by the canton of Aargau, Switzerland, which seems to be unique in its consequent focus on entire farms, aiming at increasing quality and quantity of ecological compensated areas (ECAs). In vascular plants and snails, the species richness increased during a period of 5 years on plots with AES, but not on control plots without AES. In butterflies and birds, no significant differences were found between AES plots and control plots in the change of species richness over time. While butterfly species numbers generally decreased, bird species numbers increased on both AES plots and control plots. It appears that agri-environment schemes can be effective in protecting and promoting biodiversity, but the effect may depend on the group of organisms.

Ethnic, Racial, and Gender Variations in Health Among Farm Operators in the United States

The purpose of this study was to collect baseline prevalence data on the health problems faced by minority, white, and female farm operators. An occupational health survey of farm operators was conducted by the U.S. Department of Agriculture, National Agricultural Statistics Service between February and August 2000. A stratified random sample of farm operators from 50 U.S. states based on the 1997 Census of Agriculture was selected for telephone interview. Interviews were primarily conducted using a computer assisted telephone instrument system. Population prevalences were calculated for 7137 farm operators. Prevalences were greatest for musculoskeletal discomfort, followed by respiratory problems, hearing loss, and hypertension. Generally, Latino and Asian American operators had lower prevalences for health problems than white non-Latino and white operators, respectively. African-American operators had greater prevalences for hypertension, and osteoarthritis, but lower prevalences for hearing loss, skin problems, heart problems, and cancer than white operators. American Indian or Alaska Native operators had higher prevalences for musculoskeletal problems, skin problems, and hypertension. Prevalences for the different ethnicity and race groups are not the same. Studies that combine racial and ethnic groups, or study only white and non-Latino farm operators may overestimate or underestimate the prevalence of health conditions in the entire farm operator population.

Nutritional management for enteric methane abatement: a review

A variety of nutritional management strategies that reduce enteric methane (CH4) production are discussed. Strategies such as increasing the level of grain in the diet, inclusion of lipids and supplementation with ionophores (&gt;24 ppm) are most likely to be implemented by farmers because there is a high probability that they reduce CH4 emissions in addition to improving production efficiency. Improved pasture management, replacing grass silage with maize silage and using legumes hold some promise for CH4 mitigation but as yet their impact is not sufficiently documented. Several new strategies including dietary supplementation with saponins and tannins, selection of yeast cultures and use of fibre-digesting enzymes may mitigate CH4, but these still require extensive research. Most of the studies on reductions in CH4 from ruminants due to diet management are short-term and focussed only on changes in enteric emissions. Future research must examine long-term sustainability of reductions in CH4 production and impacts on the entire farm greenhouse gas budget.

Coaching the process of designing a farm: using the healthy human as a metaphor for farm health

This paper is on coaching farmers in (re)designing a farm. It describes how farmers can become inspired to design a sustainable farm by the way medical doctors look at the human being and his health. Sustainability in farm management is usually strived for in such a way that damage to People, Planet or Profit is prevented. However, preventing such damage does not automatically mean that humans, animals, rural societies, landscape, and nature can develop and manifest themselves to the full extent. Only in examples where the emphasis is on positive characteristics of and actions in farming, and where the approach is based on coherence between the three layers described (agricultural production, agri-culture, and the meaning of life and existence), we observe that all stakeholders can fully express themselves. This approach is comparable with the positive way in which the World Health Organization describes human health, distinguishing three different layers of health: physical health, socio-cultural health, and mental health. Applying the metaphor of the healthy human enables us to ask relevant questions as to how to achieve farm health. The power of the metaphor of the living human lies in the possibility to introduce the concepts of life, the conscious direction, transformation and health in the process of (re)designing the farm organism. The living farm emerges under the direction of the farmer as a new entity in which the possibilities of the site, the societal and agro-ecological context and the people involved are all mutually fine-tuned. Only if all three interconnected layers of health (i.e., the physical, socio-cultural, and mental health) are equally addressed, true farm health, and, in our definition of farm health, also sustainability can be achieved. This paper does not address the issue of creating an absolutely healthy and sustainable farm but is about farm transformation and the art of development, step-by-step reshaping specific farm elements, thus allowing the entire farm to become healthier.

Association Between a Visual and an Automated Locomotion Score in Lactating Holstein Cows

Two studies were conducted to evaluate visual locomotion scoring (VLS) and Stepmetrix locomotion scoring (SLS) in detecting painful digit lesions. In study 1, one veterinarian performed VLS. Cows with VLS ≥3 were hoof trimmed and the presence or absence of a painful lesion (PL), defined as a reaction to digital pressure, was recorded. A strongly increasing pattern in the proportion of cows with PL was detected as VLS increased. The proportions of cows with painful lesions were 5.6% (n=53), 20.1% (n=78), 55.5% (n=164), 79.9% (n=159), and 100% (n=5) for VLS 1 to 5, respectively. Study 2 was conducted on a different farm. The entire farm was visually locomotion scored by 3 veterinarians on the same day, and the cows were Stepmetrix locomotion scored by walking through the Stepmetrix system. Every cow was trimmed during the following 2 d by 1 of 8 professional hoof trimmers. The 3 veterinarians identified, scored, and recorded any PL. Interobserver agreement for the 3 veterinarians had a kappa coefficient of between 0.45 and 0.48±0.05. In total, 518 cows were used in the analysis, from which 11.2% were identified with a PL. Of the cows diagnosed with a PL, 32.8% were detected with a sole ulcer, 25.9% with white line disease, 13.8% with white line abscess, and 27.5% with other diseases. A receiver operating characteristic analysis was performed; the area under the curve was larger for VLS (0.80; 95% confidence interval, 0.76 to 0.83) than SLS (0.62; 95% confidence interval, 0.57 to 0.66). When performed by trained veterinarians, VLS performed better than SLS in detecting PL.

Biomass management in recirculating aquaculture systems using queuing networks

Queuing network contains a series of service facilities (in our case, culture tanks or ponds), at some or all of which, a customer (fish) must receive service; it is, therefore, necessary to study the entire network. A culture tank or pond can be seen as a queuing system in which neither a queue (“over-holding” of fish in tank A before being moved to tank B), nor an idle pond is allowed, and arrival and departure rates are equal. The entire farm can be seen as a queuing network. A queuing model for optimizing the management parameters of a recirculating aquaculture system was developed. The model validity was statistically tested and was not rejected within the 95% confidence level, therefore, the model can be useful for both research and practical applications. The model aims to optimize: (1) the system layout, (2) the fish batch arrival frequency, (3) the number of fingerlings in a batch, (4) the number of days in each culture tank, and (5) grading criteria along the production lines. Under our local farm conditions we found that: the “2, 4, 8 layout” was a superior layout; the optimal operating parameters were: arrival of a batch every 36 days; 72 days at the nursery stage (up to 25 g); followed by 144 days (up to 200 g) at each successive growth phase. The optimal values maintain biomass density criterion of 80 kg m − 3 and tank utilization criterion of never below 99%.

Offshore Windmill Farms: Threats to or Possibilities for the Marine Environment

A massive development of offshore windmill farms has been planned along the European coastline. This raises important questions about the possible effects on the marine environment. Effects during the construction period may be minimized to a negligible impact if care is taken to avoid areas containing rare habitats or species. Disturbance caused by noise, vibrations, and electromagnetic fields during windmill operation may, with present knowledge, be considered to be of minor importance to the marine environment. The reef effect (i.e. addition of a hard substratum), is believed to cause the largest impact on the marine environment and at different scales: the micro scale, which involves material, texture, and heterogeneity of the foundation material; the meso scale, which involves the revetments and scour protection; and the macro scale, which encompasses the level of the entire windmill farm. Effects on these scales are discussed in relation to results obtained from natural habitats, artificial reefs, and other man-made constructions at sea.

Modelling bovine trypanosomosis spatial distribution by GIS in an agro-pastoral zone of Burkina Faso

Modelling of the spatial distribution of bovine trypanosomosis prevalence in Sideradougou district Burkina Faso was performed by using a combination of spatial and statistical analysis. Based on a comprehensive and geographically representative census of herds and farms in the area, more than 2000 cattle were randomly chosen and their blood sampled during field survey. Data on livestock farming practices were recorded for each farm. All data were mapped within a GIS to generate new information on spatial constraints in the area. Surveys results were analysed and serological prevalence data were modelled using logistic regression. The model allowed identification and quantification of risk factors. In a second step the statistical model was used predictively on the entire farm population in the area. This method was successful in predicting the serological prevalence for each individual herd in the sample, from their livestock management patterns and spatial location. Predicted prevalences were represented within the GIS, taking daily movements of animals into account. Spatial distribution of prevalence would illustrate specific locations at risk from an epidemiological viewpoint. It gives evidence that the hydrological network and land occupation patterns in the savanna-type countryside are playing an important part when structuring a so-called “trypanosomosis space”.

DETERMINANTS OF IMPROVING PRODUCTIVITY OF DRY-SEEDED RICE IN RAINFED LOWLANDS

Land and crop management practices were studied to determine yield stability and feasible measures to improve productivity of dry-seeded rice. Variability of yields among farms that had grown dry-seeded rice on the entire farm every season during the period 1991–95 was lower than among farms that had consistently grown transplanted rice during the same period. Weed control is a major challenge for dry-seeded rice and almost all farmers used herbicides to control weeds. Farmers who grew a non-rice crop before the rice season had better weed control than those who did not. Ploughing intensity and the type of implement used for land preparation were not significant factors for weed control. Field bund management was one determinant of productivity differences among farmers. The use of cross-bunds or periphery- and cross-bunds improved the efficiency of rainwater conservation and input use, and increased yields. Fields with higher levelling precision had lower water stress and produced better yields. On average, a farmer lost 0.93 t ha−1 yield due to land-levelling deficiency. The division of large and medium farms into a number of smaller plots improved levelling precision and water control, resulting in higher yields.

Monitoring nutrient flows and economic performance in African farming systems (NUTMON).: III. Monitoring nutrient flows and balances in three districts in Kenya

A nutrient balance study was carried out for 26 farms in three different districts in Kenya. Balances for the major nutrients nitrogen, phosphorus and potassium were calculated for individual activities within the farms and for the entire farms, using Farm-NUTMON, a research tool that combines calculation of nutrient flows and balances with economic farm analysis. Four flows into the farm (chemical fertilizer, organic fertilizer and feeds, atmospheric deposition, nitrogen fixation), six flows out of the farm (farm products, other organic outputs, leaching, gaseous losses, erosion and human excreta) and six internal flows (consumption of external feeds, household waste, crop residues, grazing, animal manure, and home consumption of farm products) were considered. Data on fertilizer use, use of organic materials, yields, home consumption and the management of residues, manure and household waste were gathered by interviewing the farmer. Assumptions for deposition, leaching and gaseous losses were made by using empirical relationships based on literature data (transfer functions). Erosion was estimated relating the overall slopes of the farms to soil loss figures. The mean balance of all farms was −71 kg N, +3 kg P and −9 kg K ha −1 yr −1, with large variations between farms and little variation between districts. Emissions (leaching, gaseous losses and erosion) were estimated to be much higher than immissions (atmospheric deposition and N-fixation). Inflows and outflows at field level were much higher for cash crops than for food crops. Soil nutrient mining under napier grass ( Pennisetum purpereum) was severe from high estimated losses in the napier-livestock-manure cycle. Based on an evaluation of the results of this case study, recommendations were made for improvement to the approach. Developing a sustainability indicator for soil fertility requires the nutrient balance to be linked to the actual soil nutrient stocks and other soil quality indicators.