Biodiversity in agricultural lands:
how to preserve and enhance it

Conserving and enhancing biodiversity on agricultural lands is achieved not by a single measure, but by a set of practices at the field and farm level that conserve food, shelter, and breeding grounds for organisms, and reduce the load of pesticides, fertilizers, and tillage. This approach is supported by major assessments highlighting the contributions of pollinators, soil biota, and natural enemies of pests to food production and the risks of their decline with intensification.

Terms and Frameworks

Biodiversity on agricultural lands is the diversity of organisms and their communities that are directly or indirectly related to the production of food, feed, fiber, and raw materials. In practical terms, this refers to the genetic diversity of crops and breeds, the species within and around fields, and the mosaic of habitats that remain within agricultural land. International assessments often use the term "biodiversity for food and agriculture" for this topic, emphasizing ecosystem services such as pollination, biological pest control, soil maintenance, and nutrient cycling.

Agricultural lands are almost never "pure nature," but they don’t necessarily have to be biologically poor. Many groups of organisms can thrive in an agricultural matrix if there are corridors, areas of permanent vegetation, and reduced toxic loads. It’s important to distinguish between two levels: biodiversity beneficial to crops (e.g., natural enemies of pests) and biodiversity as a conservation goal (e.g., rare species sensitive to intensive cultivation). Conflicts between these levels are possible, so solutions are often constructed as a set of compromises in a specific location rather than a single "one-size-fits-all" plan.

Why are agricultural lands losing species?

The main factors driving biodiversity loss in croplands and pastures are well described in reviews and global assessments. The most significant impact is environmental simplification: large, homogeneous fields, and the reduction of copses, meadow areas, shrubs, and watercourses. The second factor is chemical stress: insecticides, herbicides, and fungicides affect not only target organisms but also a wide range of invertebrates and microbiota, and through food chains, birds and small mammals. The third factor is mechanical disturbance: frequent plowing, soil compaction by machinery, destruction of soil-nesting insects, and disruption of fungal networks.

There are separate territorial-level drivers: fragmentation of natural areas, isolation of populations, drying of wetlands, straightening of riverbeds, and drainage, which reduces the diversity of wetland habitats and associated fauna. In the tropics, this is compounded by the expansion of agricultural land and the replacement of multi-layered agricultural systems with low-shade monocultures, which reduces the diversity of birds and insects, especially specialized groups. Where trees and a high percentage of canopy cover remain, certain animal groups survive better, although the composition of the communities changes.

There’s also a socioeconomic dimension: pressure on yields and product standards leads to the standardization of varieties, increased frequency of treatments, and the reduction of "non-productive" elements. At the same time, assessment reports emphasize that biodiversity in agricultural systems is linked to resilience to shocks — droughts, pest and disease outbreaks, and soil quality. This is why this issue is viewed not as an "add-on to environmental conservation," but as a prerequisite for long-term productivity.

Groups of organisms and their functions

Pollinators

Pollination is a regulating ecosystem service, without which some crops and wild plants cannot produce stable yields and seeds. The IPBES assessment emphasizes that a significant proportion of the world’s food crops depend on animal pollination, at least to some extent, and that wild pollinator diversity is important even where managed honeybees are abundant. It also describes the main drivers of decline: habitat loss, intensification, pesticides, pathogens, and climate change.

For a farm, the practical question is simple: where can pollinators feed and reproduce throughout the season? Flowering resources are often available for a short period of time, when the crop is in bloom, followed by a "hunger window." Without nearby forbs, shrubs, and trees that bloom at other times, pollinator numbers decline. Nesting is an additional problem: many wild bees build nests in the soil, so frequent tillage and compaction by machinery directly destroy their reproductive sites.

Natural enemies of pests

This group includes predatory and parasitic insects, spiders, some vertebrates, and microbial agents. Their role is to keep herbivorous populations below economic thresholds. Global agrobiodiversity reviews note that natural enemies of pests are a key component of ecosystem services in food production, but many countries report a decline in their numbers with intensification. Moreover, the effect usually depends on the structure of the environment: the more shelter and alternative prey outside the field, the more stable the control.

Soil biota

Soil is not a "substrate," but a living community: bacteria, fungi, protozoa, nematodes, mites, earthworms, and other groups. A number of assessments emphasize the connection between the diversity of soil biota and the multifunctionality of ecosystems and processes such as nutrient cycling and soil structure formation. For agriculture, this translates into practical aspects: aggregation, water infiltration, erosion resistance, and the ability to retain nutrients.

The loss of soil biodiversity is rarely immediately visible, but manifests itself through compaction, declining organic matter content, and increased dependence on external resources. Intensive plowing, lack of vegetation cover in winter, uneven crop rotations, and excess application of certain fertilizers alter the structure of soil communities. Therefore, biodiversity improvement measures on agricultural land almost always include soil-friendly components: cover crops, reduced tillage, and the return of organic matter.

Field-level measures

At the individual field level, measures that provide organisms with "space and time" are usually effective: where to live, what to eat, and how to survive adverse periods. Importantly, a single measure rarely produces a sustainable effect; it’s better to combine three to five elements, taking into account local conditions and production culture.

Crop rotation and crop diversity

A diverse crop rotation diversifies resources and disrupts pest and disease cycles. It also staggers tillage periods and reduces periods when the field is completely bare. Agricultural biodiversity assessments emphasize that crop and production system diversity is associated with resilience and risk reduction. In practice, this means: more legumes, including perennial crops where possible, and avoiding long series of a single crop.

Cover crops and permanent vegetation

Cover crops cover the soil outside the main cropping season, providing organic matter, root exudates, and microenvironments for soil biota. They are beneficial for pollinators if the mixture includes flowering species and if mowing does not completely eliminate flowering. Soil biota responds to such measures by increasing biological activity and improving structure, which is described in reviews on the role of soil biodiversity in ecosystem functions. In arid regions, moisture management is important: cover crops can increase competition for water, and this must be taken into account.

Reduced tillage

Reducing tillage reduces mechanical disruption of soil habitats and decreases organic matter loss. Materials on soil biota emphasize that practices such as reduced tillage and maximum vegetation cover support soil biological activity. However, no-till is not an automatic solution if it is accompanied by increased herbicide loads; therefore, it should be considered in conjunction with a weed control system.

Integrated crop protection

The goal of integrated pest management is to reduce chemical stress while maintaining an acceptable level of risk to crops. The IPBES Pollinator Assessment discusses the effects of pesticides and notes that for some groups of substances, there is data on the impact on wild pollinators under real-world field exposures. In practice, this means monitoring, setting pesticide thresholds, targeted treatments, selecting products with lower risk to non-target organisms, and rescheduling treatments for times when pollinators are less active.

Buffer strips, boundaries and flower strips

Strips of perennial vegetation along fields and watercourses provide food and shelter. Continuous flowering — a mix of species with different bloom times — is crucial for pollinators. Entomophages and spiders also value "waiting" sites for the winter and early spring. In agrobiodiversity assessments, such elements are described as part of the environment that supports ecosystem services, including pollination and biological control.

Hedges and woody elements

Shrubs and trees provide vertical structure, microclimate, nesting sites for birds, and some resources for insects. In the tropics and subtropics, woody elements are particularly associated with agroforestry: tree-based systems can support more species than simpler systems, although the effect depends on management and intensity. In temperate regions, hedges also reduce wind erosion and can act as corridors for the movement of organisms between sites.

Measures at the farm and territorial level

Field practices provide some effect, but the resilience of communities is often determined by what is happening around them: whether there are sources of dispersal, how natural areas are located, and how connected habitats are to each other.

Habitat mosaic and connectivity

If there are patches of natural or semi-natural vegetation nearby, many groups of organisms are better supported because they can "survive" unfavorable periods and then repopulate fields. This is especially true for pollinators and natural enemies of pests, which require resources outside the short cropping season. The IPBES assessment explicitly identifies habitat loss and fragmentation, as well as land-use intensification, as drivers of pollinator decline. Therefore, at the territorial level, corridors, riparian strips, forest edges, and chains of small patches that reduce isolation are important.

Agroforestry

Agroforestry is a broad class of systems where trees and crops or pastures coexist and are managed together. Reviews emphasize that such systems often enhance functional and overall biodiversity due to greater structural complexity and microhabitat diversity. However, the effect depends on specific factors, including tree density, species composition, the presence of forest layers, and the intensity of chemical treatments and grazing.

Preservation of genetic diversity of crops and breeds

Genetic diversity is a separate level of agrobiodiversity: varieties, local forms, animal breeds, and their wild relatives. International biodiversity goals emphasize the need to maintain the genetic diversity of cultivated plants and domestic animals and reduce genetic erosion. In practice, this involves seed production, collection management, support for local varieties, and the judicious use of selective breeding without resorting to total standardization.

Balance of "combination or separation"

Discussions often contrast two approaches: "combining" nature conservation with production on the same land, and "separation" — high yields on a portion of the area while preserving natural areas separately. Research shows that the results depend on the group of organisms, the region, and the structure of the agricultural territory. A European test on a large set of species in Poland showed that scenarios with the separation of natural areas can yield larger regional population sizes for some species, under certain assumptions about yield and territorial structure. In practice, this is often addressed as a combination: some measures "within the field" plus actual protected or underutilized areas nearby.

Monitoring and metrics without self-deception

Managing biodiversity without measurement is difficult: you can waste resources and create decorative elements with no real impact. However, monitoring doesn’t have to be expensive if you choose sensible indicators and stable protocols.

Field indicators

For pollinators, regular transect surveys, cup traps, and seasonal assessments of floral resources are suitable. For biomonitoring, predator and parasitoid counts are recommended, as are data on crop damage under a given level of agricultural practices. For soil, organic carbon content, aggregation, infiltration, and biological indicators, if laboratory facilities are available, are considered. A significant part of the "soil biota-function" relationship is discussed in review materials on soil biodiversity and multifunctionality.

Threshold decisions and risks

An increase in the number of individual species in a zone should not be considered a "win" for biodiversity if the overall environment remains toxic and homogeneous. It’s important to distinguish short-term effects (e.g., a year-long increase in population) from stable trends lasting 5-10 years. The carryover of effects must also be considered: some measures are effective only if dispersal sources are present in the area, which follows directly from the role of fragmentation and habitat loss for pollinators. Therefore, interpreting indicators without context is often misleading.

Economics and Management in Practice

Farmers typically make decisions through the lens of costs, risks, and labor. Therefore, biodiversity measures are more easily implemented when they are linked to clear production benefits: yield stability, reduced pest outbreaks, and soil moisture retention. IPBES emphasizes that increased pollinator density and diversity are associated with increased yields for some crops and support for food security. This logic helps to communicate with farmers in the language of "risk and return," not just "nature conservation."

The operational management model typically looks like this: a minimum set of mandatory measures (water buffers, preserving key areas), followed by two to three quick-impact measures (flower strips, adjusting tillage), and then slower soil-impact measures (cover crops, reducing tillage), which produce results over several seasons. For large areas, collective action by neighboring farms is important because habitat connectivity is not concentrated within a single field. This is directly related to the fact that the drivers of biodiversity loss lie at both the field and territorial levels.