Crop Diversification Strategies Research Articles

Effects of input subsidies on cropland allocation and diversification in Botswana’s subsistence economy

ABSTRACT Input subsidy programs (ISPs) are an important agricultural development strategy in sub-Saharan Africa (SSA). Past studies have focused on the impact of ISPs on crop production, food security and poverty. Little attention has been devoted to assessing their impact on crop diversification, which is a strategy for managing production risk and improving soil fertility under cereal-based smallholder production environments in SSA. Meanwhile, there is growing debate on whether ISPs may conflict with the crop diversification strategy by promoting crop concentration. We estimate cropland allocation and diversification models to test this hypothesis for two ISPs in Botswana, Accelerated Rainfed Arable Programme (ARAP) and Integrated Support Programme for Arable Agriculture Development (ISPAAD), using panel data of agricultural regions and the cropping seasons of 1978/79 to 2013/14. Results reveal that ISPs have induced increased concentration on cereals, away from beans/pulses and oil crops, leading to reduced cropland diversification. ARAP induced a 6.7 percentage point rise in cereal area share and a 5.2 (1.4) percentage point fall in beans/pulses (oil crops) area share. Similarly, ISPAAD induced a 4.4 percentage point rise in cereal area share and a 4.1 percentage point fall in beans/pulses area share. By discouraging legume production, ISPs may lead to soil fertility loss, as legumes may help rebuild nitrogen stocks in soils.

Innovating within or outside dominant food systems? Different challenges for contrasting crop diversification strategies in Europe.

Innovations supporting a shift towards more sustainable food systems can be developed within the dominant food system regime or in alternative niches. No study has compared the challenges faced in each context. This paper, based on an analysis of 25 cases of European innovations that support crop diversification, explores the extent to which barriers to crop diversification can be related to the proximity of innovation settings with dominant food systems. Drawing on a qualitative analysis of interviews and participatory brainstorming, we highlight 46 different barriers to crop diversification across the cases, at different levels: production; downstream operations from farm to retailing, marketing and consumers; and contracts and coordination between actors. To characterise the diversity of innovation strategies at food system level, we introduce the concept of "food system innovation settings" combining: (i) the type of innovative practice promoted at farm level; (ii) the type of value chain supporting that innovation; and (iii) the type of agriculture involved (organic or conventional). Through a multiple correspondence analysis, we show different patterns of barriers to crop diversification according to three ideal-types of food system innovation settings: (i) "Changing from within", where longer rotations are fostered on conventional farms involved in commodity supply chains; (ii) "Building outside", where crop diversification integrates intercropping on organic farms involved in local supply chains; and (iii) "Playing horizontal", where actors promote alternative crop diversification strategies-either strictly speaking horizontal at spatial level (e.g. strip cropping) or socially horizontal (arrangement between farmers)-without directly challenging the vertical organisation of dominant value chains. We recommend designing targeted research and policy actions according to the food systems they seek to develop. We then discuss further development of our approach to analyse barriers faced in intermediate and hybrid food system configurations.

Analysing the Links Between Index-Based Crop Insurance Adoption and Agricultural Investments in Burundi

This paper analyses the links between index-based crop insurance (IBI) adoption and agricultural investments based on a cross-sectional sample of 40 crop insurance adopters and 40 non-adopters from two communes located in Gitega province in Burundi. Analysed agricultural investments variables included use of fertilizers, applying crop diversification, and use of land and crop management practices in the most recent year and in the year before IBI implementation started. The results from multivariate analysis indicate that adopters use 36% more chemical fertilizers and invest 18% more in chemical fertilizers than non-adopters (p≤0.01). Adopters apply more land management practices also, in which they invest 15% more than non-adopters (p≤0.01). Furthermore, adopters change crop management practices over time by 38% and their knowledge in crop management practices increased by 23% (p≤0.01). Differences between adopters and non-adopters are however not statistically significant for crop diversification strategies and for the use of organic fertilizers. Hence, in order to be more effective and beneficial to farmers, other actions are also needed to encourage farmers to invest in their farm. Particularly promising in Burundi in this respect is to empower and train farmers by means of the Integrated Farm Planning approach, as well as to enhance farm inputs availability and to promote smart agri-entrepreneurial programs. In order to enhance agricultural development, the Burundi government should have a more prominent role in fostering farmers’ agricultural investments and in supporting IBI adoption.

Diversified Arable Cropping Systems and Management Schemes in Selected European Regions Have Positive Effects on Soil Organic Carbon Content

In the last few decades, various crop diversification strategies and management practices have been promoted to improve or at least maintain environmental quality and agroecosystem services. We conducted a data-analysis to evaluate the effectiveness of alternatives for crop diversification and environmentally friendly farming management for arable crops in four selected European pedoclimatic regions and typical cropping systems in the Atlantic, Boreal, Mediterranean North, and Mediterranean South regions. The dataset was retrieved from 38 references and included data on site-specific environmental conditions, soil tillage, crop rotation, fertilization, and final soil organic carbon content (SOC). No tillage (NT) was more effective (7%) in increasing SOC content than minimum tillage (MT) across the studied depths (from 5 to 40 cm). Conservation tillage as whole, including NT, MT, and rotational tillage (RT) positively affected SOC content in the top 10 cm (28%) in comparison with conventional tillage (CT). Compared to monoculture, longer crop rotations (3–5 years) and the introduction of legumes resulted in higher increases in SOC contents (18%), that were higher in semiarid conditions (11%) than under humid and sub-humid climates (3.2%). The effect of fertilization on SOC contents was higher in the Mediterranean North region (28%), and organic fertilization showed the highest increases (25%) compared to the control with mineral fertilization. Higher increases in SOC contents with tillage and fertilization management were found in sites with lower SOC contents in the control treatment (conventional tillage and mineral fertilization respectively). The data analysis indicated that various European arable agroecosystems benefit both from diversified cropping systems and the adoption of environmentally friendly farming management and are thereby capable to increase SOC contents.

Intra-seasonal climate variability and crop diversification strategies in the Peruvian Andes: A word of caution on the sustainability of adaptation to climate change

Abstract Agricultural systems are highly sensitive to climate change. Most studies focus on the effect of heat and water availability on crop yields, but little is known about the impact of changes in intra-seasonal climate variability (particularly challenging in mountain regions). Also, beyond the effect on crop yields –mostly focused on single cropping systems and major world crops- little analysis has been done on more complex, diversified and low-input cropping systems like those prevalent in the Andean region. This study investigates whether Andean farmers respond to increasing climate variability by increasing crop diversity (measured by intercropping and crop diversification indices) and by switching to crops which better tolerate heterogeneous environmental conditions. Since previous studies show that crop diversification fosters resilience of agricultural systems, decreasing crop portfolio diversity in an increasingly variable environment may challenge farms sustainability. The data used in the analysis combines district-level socio-economic information from two agrarian censuses (1994 and 2012) with district-level climate estimates of mean temperature, temperature range and precipitation (averages for periods 1964–1994 and 1982–2012). Based on fixed effects models that allow for sub-region parameter heterogeneity, I find that an increase in intra-seasonal climate variability leads farmers in colder areas (

Heterogeneous impact of livelihood diversification on household welfare: Cross-country evidence from Sub-Saharan Africa

Abstract This article investigates the empirical linkages between crop and livelihood diversification strategies, extreme weather events, and household welfare using a unique dataset that integrates harmonized, national representative household surveys and geo-referenced climatic information collected in Malawi, Niger and Zambia. In doing so, the paper addresses the potential endogeneity arising from the selection bias and the heterogeneity of the effect across the quantiles of the income distribution. Results show that exposure to extreme rainfall events is positively associated with either crop or livelihood diversification in all the countries analyzed, suggesting that climate-related shocks are key push factors for diversification. Moreover, results show that the effect of diversification on household income are varied across countries and diversification strategies. However, most of this heterogeneity disappears when estimating the quantile treatment effects. In particular, the results show that the impact of both crop and income diversification on households’ welfare is generally higher for the poorest (people located at the bottom tail of the distribution) while it decreases, and in some cases turns to be negative, moving toward the upper end of the income distribution in all three countries. The findings, therefore, highlight the pro-poor impact of diversification strategies in multiple rural African contexts, as well as the need to tailor diversification interventions toward specific socio-economic segments of the rural population.

Unpacking the push-pull system: Assessing the contribution of companion crops along a gradient of landscape complexity

The push-pull system, a stimulo-deterrent cropping strategy consisting of intercropping cereals with herbaceous legumes and surrounded by fodder grasses, is presented as a promising crop diversification strategy for smallholder farmers in Africa as it may contribute to maize stemborer Busseola fusca (Fuller) suppression, while improving soil fertility and providing feed for livestock. The push-pull system has often been assessed at plot level and as a package (e.g., Maize + Desmodium + Napier grass). However, it is unclear how the system performs in different landscape settings or when companion crops are changed to better meet household needs. Here we evaluate the potential of the push-pull system to suppress maize stemborer infestations in three landscapes in the Rift Valley region of Ethiopia along a gradient of landscape complexity. Within each landscape, experimental plots were established on four representative smallholder farms. At each farm we used a split-plot factorial design with main plots surrounded or not by Napier grass, and subplots consisting of sole maize, maize-bean or maize-Desmodium. We assessed stemborer infestation level and maize grain and stover yields during two years, as well as natural enemies abundance and egg predation at two maize development stages in the second year. In the simple landscape, which was dominated by maize, all treatments had high stemborer infestation levels, irrespective of within-field crop diversity; the presence of Napier grass was associated with higher predator abundance, while egg predation rates were the highest in the maize-bean intercrop. In the intermediate complexity landscape, subplots with sole maize had higher stemborer infestation levels compared to maize-bean or maize-Desmodium. In the complex landscape, infestation levels were low in all treatments. However, none of these effects led to significant differences in maize grain and stover yields among treatments in any of the landscapes. The benefits of the push-pull system accrued from the companion crops (bean, Desmodium and Napier), rather than from stemborer suppression per se. Our findings highlight the importance of the surrounding landscape in mediating the performance of the push-pull system, provide new insights on the contribution of the different components of push-pull system and can guide the design of ecologically intensive agroecosystems.

Crop Diversification Strategy to Improve Economic Value in Brazilian Sugarcane Production

Core Ideas The authors evaluated economically different treatments for sugarcane renewal. The authors present the impact of the diversification on sugarcane production on venture risk. The authors used the real options theory with a polynomial approach to model the managerial flexibility in exchanging sugarcane with soybean. Crop diversity is beneficial to rural properties in terms of reducing business risks and increasing agricultural revenues. In sugarcane (Saccharum spp) farming, crop diversity using rotation or succession planting remains a paradigm for rural producers, largely because the productive cycle of sugarcane differs from that of annual crops, obliging farmers to grow it for between 4 and 6 yr to compensate for the high initial investment in planting. Sugarcane producers in Brazil only plant another crop at the end of the cycle to renew the plantation. The present study questions this paradigm by using the real options theory to capture the value of managerial flexibility in diversifying production to minimize risk and increase revenue by alternating between sugarcane and soybean (Glycine max) crops, considering a polynomial model that combines market and yield volatility. To that end, the research data were based on an experiment performed over 6 yr using different sugarcane succession systems on a rural property in the region of Jaboticabal, São Paulo, Brazil. Results suggest that succession planting of soybean/crotalaria/soybean/sugarcane exhibited the best agronomic and economic–financial performance and that diversifying crops using the portfolio theory increased the value of the project. Greater return on investment was obtained by replacing sugarcane with soybean, making it possible to opt for the crop change at the third cane cutting, a completely new scenario in Brazil, the largest sugarcane producer in the world.

Farmers’ risk preference and the adoption of risk management strategies in Northern Ghana

The study used the hypothetical lottery-choice questions to measure risk aversion and a detailed survey collected data on input use, farm production and non-farm activities to specifically assess whether risk aversion, risk perceptions, and socioeconomic factors affect the risk management strategies of farm households in Northern Ghana. Risk aversion significantly increases crop diversification strategies of households but marginally reduces herbicide use by households. Market risk significantly increases the use of improved seed varieties and the application of inorganic fertiliser but reduces diversification into livestock production. Production risk largely increases diversification into livestock production. Farmers’ risk management strategies are affected by socioeconomic variables such as access to extension services, area cultivated, age and gender. Policy effort focused on building pliable on-farm crop related risk management strategies should aim at considering the risk aversion and the perception of market risk whilst those focused on livestock should focus on production risk.

Can Social Capital influence Smallholder Farmers’ Climate-Change Adaptation Decisions? Evidence from Three Semi-Arid Communities in Burkina Faso, West Africa

This study examines the influence of farmers’ social capital on their decisions to deal with climate change and climate variability in Burkina Faso. The study is based on a household survey conducted among 450 households, randomly selected from three communities in Burkina Faso. Two indexes were constructed to capture farmers’ structural and cognitive social capital; and using generalized Poisson regression (GPR) and a multivariate probit model, the study probes the effect of farmers’ social capital on their choice of adaptation alternatives, the number of adaptation practices used, and the extent to which adaptation measures were applied. The results indicated that the effect of social capital depends on the type of indicator used and on the type of adaptation strategies necessary. Farmers’ cognitive social capital was significantly and positively related to their choice of soil and water conservation techniques (SWCT), and techniques such as agroforestry and irrigation. Structural social capital, on the other hand, was positively associated with the adoption of new varieties and conservation tillage strategies and negatively associated with the use of a crop-diversification strategy. The results also highlighted that socio-economic, institutional and agro-ecological variables determine farmers’ decisions to adapt to climate change.

The regional weed vegetation in organic spring-sown cereals as shaped by local management, crop diversity and site

Mecklenburg Vorpommern has one of the highest percentages of organic arable production nationwide. Weeds remain to be the main challenge within this agricultural system. There is also an increase in the national support of agrobiodiversity. Weeds should therefore be continuously kept within manageable limits, while on the other side encourage a specie rich weed flora. Our objective is to investigate to which extent these two aspects can be addressed through the use of diversified crop management. In order to research this objective, weed and management data of spring sown cereal crops were obtained from organic farms in the region over the course of two years (2015-2016). The impact of the local environment and management factors on the occurring weed communities was studied in multivariate analysis approaches, followed by the separate crop diversity effects. We found a fundamental difference between the workings of the short-term management, the long-term crop diversification strategies and the more continuous site variables on the weed vegetation. Weed densities were mostly affected by direct management, while weed diversity and communities were altered through the application of crop diversity variables.

Irrigation and crop diversification in the 25 de Setembro irrigation scheme, Mozambique

Crop diversification is one way of improving the profitability of small-scale irrigation schemes. The 25 de Setembro scheme is an ideal site to analyze diversification, as it is influenced by the markets in Maputo and South Africa. This study uses information gathered from observations, discussions with irrigators and an irrigator survey. Results identified seven irrigator types with different crop diversification strategies predominantly influenced by resource constraints. Most irrigators produce traditional crops, although there are opportunities for growing crops that are more profitable. Improved extension services, to identify cropping strategies that better align with market demand, would improve profitability.

SUSTAINABLE DIVERSIFIED AGRICULTURE AND LAND MANAGEMENT IN THE HIMALAYA: IMPLICATIONS FOR CLIMATE CHANGE ADAPTATION AND MITIGATION

The soil and land resources play a vital role in sustaining the local livelihoods of rural communities in the Himalaya. Most of the arable land has already been brought under cultivation, hence the ever-increasing demand for food and fiber has left farmers with no choice but to intensify agriculture. However, producing more crops and greater quantities of food, fiber and other materials on the same parcel of land can to soil fertility and productivity decline with overall degradation of land quality. Therefore, ways and means to intensify agriculture to enhance productivity without degrading the soil and land resource base have become imperative. Agro-forestry, agro-slivi-pastoral systems, and the adoption of a variety of crop, soil and water management and conservation practices offer potential to deliver multiple benefits without sacrificing the very resource upon which the human population depends. Presented herein are findings on approaches to sustainable intensification of agriculture and land management related to soil OM management and C sequestration for multiple benefits, and, agro-forestry as a crop diversification strategy with both livelihood, and climate change adaptation/mitigation benefits. The results indicate that sustainable soil management practices could lead to significant SOC accumulations (4-8 t/ha over 6 yrs). SOC and soil C stocks tend to increase with elevation due to cooler climate and slow decomposition rates. Carbon stocks for the 3 LU types was in the order CF>AF/LH>AG, suggesting that diversified cropping practices including agro-forestry have good potential sequester C while providing livelihood opportunities and climate adaptive capacity for local farming communities. Biochar amendment increased growth of both coffee plants and radish with mixed grass/weed biochar being most effective. Biochar application also significantly decreased emission of GHGs, especially N2O.

Field scale functional agrobiodiversity in organic wheat: Effects on weed reduction, disease susceptibility and yield

Abstract Deployment of diversity at the species and at the genetic levels can improve the ability of crops to withstand a wide range of biotic and abiotic stressors in organic and low-input cropping systems, where the response to stresses through external input is limited or restricted in comparison with conventional systems. Although there are several strategies to use agrobiodiversity in wheat-based systems, their implementation is limited by the lack of a clear relationship between agrobiodiversity and provision of key agroecosystem services. In a three-year field trial in Central Italy we compared common wheat Italian and Hungarian pure lines, Italian old cultivars and Hungarian and British Composite Cross Populations (CCPs), grown with or without a contemporarily sown Subterranean clover living mulch. We aimed at linking crop performance, in terms of yield, weed reduction and disease susceptibility, to three categories of functional diversity: (1) functional identity, represented by the identifying traits of cultivars, (2) functional diversity, represented by the genetic heterogeneity of wheat crop population, and (3) functional composition, represented by the co-presence of wheat and the living mulch. Concerning cultivars, effects of functional identity were predominant for weed reduction and grain yield. Old cultivars tended to better suppress weeds but to be less yielding. Italian cultivars were more advantaged than cultivars of foreign origin, thanks to a better matching of their growth cycle into local climate. Functional diversity effects on yield and weed reduction were confounded with identity effects, given that all the CCPs were of foreign origin. In fact, the performance of CCPs was generally aligned with a central-European pure line. However, differences in yield components suggest that CCPs can evolve peculiar yield formation strategies. Moreover, CCPs were less susceptible than pure lines to foliar diseases. For functional composition, the living mulch was able to reduce dicotyledonous weed abundance and weed biomass without reducing wheat yield unless wheat was poorly established. Despite the strong morphological and phenological differences among the tested cultivars, no interactions were found between cultivar and living mulch presence, suggesting that, in conditions similar to our experiments, there is room to freely combine elements of crop diversity. Crop diversification strategies in wheat should be further explored and optimized, especially by constituting CCPs from locally adapted germplasms and by improving the feasibility and efficacy of legume living mulches.

New Approaches and Strategies for Irrigation Water Management

The depletion of groundwater resources can seriously hinder the availability of irrigation water in India and can thus adversely affect agricultural productivity, jeopardizing the food security efforts. To meet the future demand for food production India must circumspectly manage its water resources and try saving and conserving water, particularly for irrigated agriculture; enhancing use-efficiency of surface and ground water; improving groundwater recharge; and using waste waters with safety. This paper discusses issues related to irrigation water management and focuses on innovative practices, strategies and approaches. The technological advances in the area of super absorbent polymer hydrogel, lining of canals and field channels; breeding short duration and drought tolerant aerobic rice varieties; strategies for using wastewater, use of remote sensing technologies are highlighted. The issues like crop diversification, mitigation and adaptation strategies dealing with climatechange and the relevance of virtual water trading are discussed in an Indian perspective. The governmental policy decisions to arrest the trends of rapidly falling groundwater along with their impact are also discussed.

Increasing crop diversity mitigates weather variations and improves yield stability.

Cropping sequence diversification provides a systems approach to reduce yield variations and improve resilience to multiple environmental stresses. Yield advantages of more diverse crop rotations and their synergistic effects with reduced tillage are well documented, but few studies have quantified the impact of these management practices on yields and their stability when soil moisture is limiting or in excess. Using yield and weather data obtained from a 31-year long term rotation and tillage trial in Ontario, we tested whether crop rotation diversity is associated with greater yield stability when abnormal weather conditions occur. We used parametric and non-parametric approaches to quantify the impact of rotation diversity (monocrop, 2-crops, 3-crops without or with one or two legume cover crops) and tillage (conventional or reduced tillage) on yield probabilities and the benefits of crop diversity under different soil moisture and temperature scenarios. Although the magnitude of rotation benefits varied with crops, weather patterns and tillage, yield stability significantly increased when corn and soybean were integrated into more diverse rotations. Introducing small grains into short corn-soybean rotation was enough to provide substantial benefits on long-term soybean yields and their stability while the effects on corn were mostly associated with the temporal niche provided by small grains for underseeded red clover or alfalfa. Crop diversification strategies increased the probability of harnessing favorable growing conditions while decreasing the risk of crop failure. In hot and dry years, diversification of corn-soybean rotations and reduced tillage increased yield by 7% and 22% for corn and soybean respectively. Given the additional advantages associated with cropping system diversification, such a strategy provides a more comprehensive approach to lowering yield variability and improving the resilience of cropping systems to multiple environmental stresses. This could help to sustain future yield levels in challenging production environments.

Crop Diversification in Coping with Extreme Weather Events in China

Apart from the long-term effects of climate change, the frequency and severity of extreme weather events have been increasing. Given the risks posed by climate change, particularly the changes in extreme weather events, the question of how to adapt to these changes and mitigate their negative impacts has received great attention from policy makers. The overall goals of this study are to examine whether farmers adapt to extreme weather events through crop diversification and which factors influence farmers' decisions on crop diversification against extreme weather events in China. To limit the scope of this study, we focus on drought and flood events only. Based on a unique large-scale household survey in nine provinces, this study finds that farmers respond to extreme weather events by increasing crop diversification. Their decision to diversify crops is significantly influenced by their experiences of extreme weather events in the previous year. Such results are understandable because farmers' behaviors are normally based on their expectations. Moreover, household characteristics also affect farmers' decisions on crop diversification strategy, and their effects differ by farmers' age and gender. This paper concludes with several policy implications.

Economic valuation of maize farming profitability under climate change adaptation in Benin, West Africa

The major attempt of this paper is to analyse the profitability of maize farming in relation with observed climate change adaptation strategies. The study was conducted in Benin by a survey method on 336 maize producers. About 91% of the respondents undertook at least one adaptation strategy towards climate change. The observed strategies were categorised in four groups, including crop diversification, farming practices and calendar adjustment, land use strategies, and other adaptations (e.g. prayers, credit, and migration). Maize farming in the study zone was found to be profitable. Yet, the economic performances recorded by farmers were correlated with some of the climate change adaptation strategies. Crop diversification strategy was found as the most interesting adaptation to improve the farm economic profitability. Hence, research institutes and policy makers should work for providing crop varieties better adapted to climate change, especially to drier conditions, as to facilitate crop diversification behaviour among farmers.

An integrated hydro-economic modelling framework to evaluate water allocation strategies II: Scenario assessment

In this paper the results of an assessment of the hydrological and economic implications of reallocating water in the Musi sub-basin, a catchment within the Krishna Basin in India, are reported. Policy makers identified a number of different but plausible scenarios that could apply in the sub-basin, involving; supplying additional urban demand from agricultural allocations of water, implementing a number of demand management strategies, changing the timing of releases for hydropower generation, changing the crops grown under irrigation, reducing existing stream flows and allowing for more environmental flows. The framework chosen to undertake this assessment was a simulation model that measures and compares the economic values of water allocation scenarios determined from a water allocation model that accounts for supplies of groundwater and surface water across a number of regions and over a variety of uses. Policy makers are provided with the range of measures on the security of the supply of water and the social costs and benefits of reallocating water between sectors and across regions within the sub-basin. Taking water from agriculture to supply urban users has a greater impact on irrigation supplies during dry years. It was also found that changing the allocation of water between sectors, by taking it away from agriculture had a large positive economic impact on the urban sector. Yet the costs involved in undertaking such a strategy results in a significant loss in the net present value of the scheme. Stream flow reductions, if significantly large (at around 20%), were found to have a large physical and economic impact on the agricultural sector. Implementing water saving strategies in Hyderabad was found to be more cost effective than taking water from agriculture, if rainwater tanks are used to achieve this. Changing the timing of hydropower flows resulted in best meeting of irrigation demand in NSLC and NSRC. Under this scenario, the crops grown under irrigation were found to have a significant economic impact on the sub-basin, but not as large as farmers undertaking crop diversification strategies, ones which result in farmers growing less rice. The security of supplying water to different agricultural zones has significantly improved under this scenario. Finally, releasing water for environmental purposes was found to have only a minor impact on the agricultural sector.

Host location and oviposition of lepidopteran herbivores in diversified broccoli cropping systems

Abstract1 Host location and oviposition are crucial steps in the life cycles of insect herbivores. A diversified cropping system may interfere with these processes, ultimately reducing pest colonization of crops and the need for chemical interventions.2 In the present study, nonhost vegetation was added to a broccoli (Brassica oleracea var. italica) cropping system to determine the effect of plant diversification on host location and colonization of broccoli by Lepidopteran pests. The two diversification strategies applied consisted of a broccoli/potato (Solanum tuberosum) strip crop, made up of 1.65 m (tractor width) replications of two rows of potatoes and two rows of broccoli, and a cereal rye (Secale cereale) cover crop, which formed a sacrificial planting that was killed and rolled flat to minimize weed competition and improve the agronomic performance of the subsequent broccoli crop.3 Diamondback moth Plutella xylostella eggs, and subsequent larvae and pupae, were less abundant on broccoli with the cover crop, probably due to interference with host location and oviposition processes. The strip crop had no effect.4 Numbers of cabbage white butterflies Pieris rapae eggs and larvae did not differ among treatments, probably due to the superior ability of these Lepidoptera to visually locate hosts and their active egg‐dispersing behaviour.5 These results of the present study indicate that the success of crop diversification strategies are contingent on the relative ability of the target herbivore to locate its host plant and the scale of diversity (e.g. the distance between the host and the nonhost plants), rather than diversity itself.