Steven Vanek

• PhD Soils, Cornell University, 2011
• Researcher at Colorado State University

The need to increase agricultural production for food, fiber, and feed for a growing population is a global call. Sub-Saharan Africa currently experiences declining soil fertility and increasing pest pressures affecting agricultural production. Soil fertility and pest management practices tend to vary greatly among smallholder farmers due to farm-b...

Introduction Soil-borne pathogens cause considerable crop losses and food insecurity in smallholder systems of sub-Saharan Africa. Soil and crop testing is critical for estimating pathogen inoculum levels and potential for disease development, understanding pathogen interactions with soil nutrient and water limitations, as well as for developing in...

Common bean production is constrained by a multitude of biotic constraints including bean flies and Fusarium wilt in tropical and subtropical farming systems globally. As these pests and diseases attack the crop beneath the soil, excessive applications of synthetic pesticides are frequently used for their control. The use of plant-based pesticides...

Global changes, particularly rising temperatures, threaten food security in smallholder mountain communities by impacting the suitability of cultivation areas for many crops. Land-use intensification, associated with agrochemical use and tillage, threatens soil health and overall agroecosystem resilience. In the Andean region, farmers often cultiva...

Understanding drivers of nutrient balances in cropping systems, and possible strategies to replenish nutrient and carbon losses from soils, is crucial for maintaining and improving soil health. We determined nitrogen, phosphorus, and potassium balances, likely trajectories of soil organic carbon (SOC) and implications of alternative management scen...

Intensification of crop rotations and associated agricultural practices are reducing the capacity of traditional fallows to restore soil fertility and provide forage in Andean cropping systems. While the implementation of improved fallows offers great promise to enhance forage provision and maintain soil productivity, effects of these practices on...

Accessible, high-quality seed is vital to the agricultural, food, and nutrition sovereignty needed for justice-based sustainable development. Multiregion, interdisciplinary research on farmers' seed systems (FSS) can complement case-based and thematic approaches.This study's goals are to (1) provide a synthetic overview of current major FSS concept...

Introduction Pests and diseases limit common bean ( Phaseolus vulgaris ) production in intensifying smallholder farming systems of sub-Saharan Africa. Soil-borne pests and diseases (SPD) are particularly challenging for farmers to distinguish and manage in cropping systems that vary in terms of soils, farmer knowledge, and management factors. Few s...

Trees can have important impacts on multiple ecosystem services and biodiversity in agricultural landscapes. The influence of trees can extend beyond forested areas and into adjacent land uses, however, this is rarely accounted for in the ecological literature. To better understand the influence of trees in Andean agroecosystems, we examined altern...

Continuous inputs of organic matter are vital for sustaining soil organic carbon (SOC) and productivity of soils in smallholder crop-livestock systems. However, the dynamics of the different inputs i.e. maize shoots, roots and manure used are poorly understood. Along with organic inputs, use of mineral fertilizers can alter the nutrient stoichiomet...

This study analyses the experience and response of farmers within a multi-year collaborative research trial focused on the development of forage-based fallows in eight communities in the central Peruvian Andes. Quantitative data from a rural household survey were used to characterize farming household socioeconomic factors, livelihood strategies an...

Due to its multiple functions, soil macrofauna plays a major role in the functioning of agroecosystems. However, its abundance and diversity can be influenced by various human activities such as agricultural practices. This study, initiated on ferric lixisols in the Sudano-Sahelian zone of Burkina Faso, aims to evaluate the effects of four agroecol...

Aim Macroinvertebrates comprise a highly diverse set of taxa with great potential as indicators of soil quality. Communities were sampled at 3,694 sites distributed world‐wide. We aimed to analyse the patterns of abundance, composition and network characteristics and their relationships to latitude, mean annual temperature and rainfall, land cover,...

Soils of the Andean highlands are under threat from cropping system intensification. Improved forage-based fallows offer great promise to address this issue, but research is needed to better understand the potential of species mixtures vs. monocultures to support multiple farmer objectives, especially forage production and soil conservation. We use...

Rural households across the world are increasingly turning to off-farm sources of income to complement or replace farm income. A better understanding of these livelihood adaptations, their consequences, and the processes behind them will facilitate more effective rural development policies and projects. The objective of this research was to examine...

Organic nutrient sources (ONS) are managed as a key resource by smallholder farmers to maintain the productivity of soils. Recycling of ONS by applying them to soils is a globally dominant strategy of ecological nutrient management. Understanding how ONS produced on-farm are allocated and what drives farmer decision making around their use is criti...

Intensified rotations and increased reliance on agrochemical inputs in many parts of the Andean highlands generate concern for soil health, biodiversity, and key ecosystem functions that are essential for maintaining agricultural productivity and the well-being of smallholder communities throughout the region. Improved management of perennial veget...

Smallholder farmers often face challenges in managing soil fertility due to limited inputs and high spatial variability on their farms. While improved knowledge of soil constraints could help them manage limited resources more effectively, formal soil analyses are typically out of reach due to high costs of testing and transport associated with reg...

Soil fertility in agricultural landscapes is driven by complex interactions between natural and anthropogenic processes, with organic matter (OM) inputs playing a critical role. Asymmetric allocation patterns of these resources among communities and within individual farms can lead to soil fertility gradients. However, the drivers and consequences...

Land use intensity is increasing in Andean smallholder systems, and innovations are needed to sustain soil fertility and productivity of potato-cereal rotations with shortening fallow periods. In collaboration with farmers in central Peru, we assessed forage-based fallows in 58 fields across three production zones over three years. Fallow treatment...

A poor understanding of the interactions between biophysical and social elements within rural mountainous landscapes can lead to suboptimal management and recommendations. The objective of this study was to contribute to more contextualized natural resource management in a rural landscape in the Ecuadorian Andes by (1) identifying biophysical patte...

The Rural Household Multiple Indicator Survey (RHoMIS) is a standardized farm household survey approach which collects information on 758 variables covering household demographics, farm area, crops grown and their production, livestock holdings and their production, agricultural product use and variables underlying standard socioeconomic and food s...

Cover photo

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, a...

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, a...

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, a...

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, a...

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

Over the past few decades elite strains of rhizobia have become commercially available for agricultural production. However, these elite rhizobia are often not as competitive as native strains under adverse edaphic conditions, primarily concerning tolerance to soil desiccation. Biochar has been proposed as a soil amendment to reduce water stress. T...

Experts discuss the challenges faced in agrobiodiversity and conservation, integrating disciplines that range from plant and biological sciences to economics and political science. Wide-ranging environmental phenomena—including climate change, extreme weather events, and soil and water availability—combine with such socioeconomic factors as food po...

Agrobiodiversity supports agriculture globally and is used and stewarded worldwide by farming communities that possess traditional knowledge about their crops. This chapter takes an evolutionary ecological perspective on the ecology, use, and conservation of crops and proposes research objectives to advance the study of agrobiodiversity globally. I...

This chapter identifi es major areas of impact from agrobiodiversity at crop inter- and intraspecific levels on agroecosystem functioning relevant to management and resilience of cropping systems. Impacts from biodiversity on agroecosystem function are summarized as are impacts from pollination services, pest and disease impacts and resistance, soi...

Smallholders are crucial for global sustainability given their importance to food and nutritional security, agriculture, and biodiversity conservation. Worldwide smallholders are subject to expanded telecoupling whereby their social-ecological systems are linked to large-scale socioeconomic and environmental drivers. The present research uses the s...

Land use change and intensification in agricultural landscapes of the Andean highlands have resulted in widespread soil degradation and a loss in soil-based ecosystem services and biodiversity. This trend threatens the sustainability of farming communities in the Andes, with important implications for food security and biodiversity conservation thr...

We use an original geographic framework and insights from science, technology, and society studies and the geohumanities to investigate the development of global environmental knowledge in tropical mountains. Our analysis demonstrates the significant relationship between current agrobiodiversity and the elevation of mountain agroecosystems across m...

Aims The objectives of this study were to evaluate (1) the fertilizer potential of bone char, (2) the effects of wood biochar on plant-available phosphorus (P), and (3) the role of root-mycorrhizae-biochar interactions in plant P acquisition from a P-fixing soil. Methods Incubation and pot experiments were conducted with a P-fixing soil and maize w...

SUMMARY This research sought to link Andean soil knowledge and farmer categorization of soil fertility to soil science characterization of soils, and use these to understand the impacts of phosphorus (P) fertilization of legumes using rock phosphate and soluble P fertilizer in 17 smallholder-managed sites with varying soil properties. We found that...

To sustain the livelihoods of smallholder farmers globally, improved human nutrition must not sacrifice future agroecosystem productivity. We gathered environmental, agricultural management, food security (FS), and normalized child height for age (HAZ; children age < 2y) data from 297 farming households to test whether enhanced FS and nutrition goa...

Scientific and policy interest in the biological diversity of agriculture (agrobiodiversity) is expanding amid global socioeconomic and environmental changes and sustainability interests. The majority of global agrobiodiversity is produced in smallholder food-growing. We use meta-analyses in an integrated framework to examine the interactions of sm...

Research examining biochar (pyrolyzed biomass) as a microbial inoculant carrier may enable broader use of inoculant microbes and elucidate relationships between non-spore forming bacteria, such as rhizobia, and their microhabitats in carriers and soils. We tested 32 biochars as habitat for Rhizobium tropici (CIAT 899) to quantify the effects of por...

Background and aims We sought to understand biochar’s role in promoting plant phosphorus (P) access via arbuscular mycorrhizas (AM), focusing on whether P solubility and biochar-P proximity altered AM enhancement of P uptake in a mycorrhizal crop legume. Methods A greenhouse study compared feedstock-derived P with 50 mg P pot−1 of sparingly solu...

Significance Integrated pest management (IPM) has been the dominant crop protection paradigm promoted globally since the 1960s. However, its adoption by developing country farmers is surprisingly low. This article reports 51 potential reasons why, identified and prioritized by hundreds of IPM professionals and practitioners around the world. Stakeh...

Sustainable nutrient cycling in agroecosystems combining grazing and crops has global ramifications for protecting these ecosystems and for the livelihoods they support. We sought to understand environmental, management, and social drivers of nutrient management and sustainability in Andean grazing/crop systems. We assessed the impact of farmer wea...

Small farmers in the high Andes (> 2500 m) of Bolivia, Ecuador, and Peru face increasing threats to their livelihoods due to land degradation, climate change, and overall decreases in agricultural productivity. The fragile nature of these agroecosystems and limited capacity of resource-poor farmers in the region to adopt the large-scale use of conv...

Global climate change represents a major threat to sustainable farming in the Andes. Farmers have used local ecological knowledge and intricate production systems to cope, adapt and reorganize to meet climate uncertainty and risk, which have always been a fact of life. Those traditional systems are generally highly resilient, but the predicted effe...

Cover: New Leaf Farm apprentices and farmers harvesting salad greens. They are harvesting a row that has had its white row cover removed. The row cover is used to keep out flea beetles and other insect pests and to extend the growing season.

Growing a main vegetable crop for harvest and a cover crop for residue return to soil in the same growing season is a promising strategy to sustain soil quality in vegetable rotations. Our research evaluated cover crop strips interseeded between pumpkins (Cucurbita pepo L.) as a way to implement such a strategy. Cover crop types were lana vetch (Vi...