Conservation Agriculture Research Updates - April 2026

This paper from Europe used a Meta-analysis to to evaluate the impact of management practices related to carbon and nutrient, vegetation, pest and disease and soil management, as well as grazing management on soil biota and soil biology. They screened 698 articles and came up with 90 that were eligible with a total of 790 pairwise combinations and 74,526 observations. Their study showed what agricultural practices improve or reduce soil biology that is useful for selection of sustainable farming systems. They found that reduced tillage, organic fertilization, cover cropping and intercropping resulted in positive improvements in soil health factors. They also developed a “Utility-Robustness” scoring system for soil actors, using a systematic framework to inform biological indicator selection tailored to specific management contexts.

This study using maize and barley looked at the effect of various seed treatments (pesticides) had on roots and soil microbiota under CA. Seed treatments consisted of various commercial pesticide mixtures compared to a non-treated check. Soil and root samples were taken 2-3 times during the season and measurements taken on root biomass, root mycorrhizal fungi and pathogens, soil microbes and nematodes. They conclude that the pesticides and seed treatments had limited effects on root and soil microbiota.

This article used the agro-hydrological Daisy model to look at degradation and leaching of pesticides under CA and conventional scenarios. Using a Daisy soil column they took measurements of topsoil, mulch and a realistic subsoil and tested against published experimental data pesticide fate in laboratory soil columns. Results showed no systematic difference in pesticide leaching from the topsoil between CA and CT, but pesticide degradation and sorption were significantly different; degradation in the mulch and uppermost soil surface layer (0–3.5 cm) was larger in CA while degradation was larger in CT when considering the whole topsoil (0–30 cm). 

The increase in use of CA practices (NT, residue, cover crops) in North America has in some cases resulted in an increase in damage by slugs. This paper tested the use weather and natural enemies on slug activity in 41maize and soybean fields in Virginia. They found that a positive effect of cover crops on slug activity-density was reduced by tillage and that slug activity-density declined with increasing ground beetle activity-density. Slug activity-density also declined with decreasing rainfall and increasing average temperature. They conclude that practices that promote recruitment of ground beetles in crop fields can improve natural suppression of slugs in corn and soybean that are being increasingly cultivated using conservation agriculture practices.

This paper looks at the role of CA in pest management of maize in South Africa. This study employed a component omission approach to investigate the probable effects of crop residue management on insect pest populations in a maize-based cropping system. Field experiments were carried out on an ongoing CA trial. Main plots had two tillage levels, sub-plots 4 different rotations, and sub-sub plots two residue management levels. For the conventional tillage study, two levels of crop rotation and residue management were considered as the different CA adoption levels by smallholder farmers. Results showed that crop rotation and residue management influence arthropod abundances, diversity, richness, and evenness, which can be used to predict or monitor pest outbreaks. But, the synergistic influence of environmental/climatic regimes cannot be separated from the individual agronomic practices. 

This is an important paper for CA that explains why rotation should still be used in the three pillars of CA. This paper looks at disease control options for Fusarium Crown rot (FCR) of wheat in South Africa. They look at rotation and tillage as two methods to control this disease. For crop rotation they used non-host crops like annual medics, canola, and lupin with all three significantly reducing FCR incidence and severity in wheat while increasing yield and quality. 4 tillage treatments were used - conventional tillage (deep soil disturbance with a plough), minimum tillage (shallow tine tillage), no tillage (no primary soil disturbance, tine planter) and zero tillage (no primary soil disturbance, disc planter). Both no-tillage treatments decreased FCR incidence and disease severity. The authors suggested that better soil water conservation later in the season, along with shallower seeding depth in no tillage, contributed to FCR disease management. Rotation still needs to be kept when defining CA because of its importance for disease, pest and weed control.

This study used an integrated network to show how the reduction of tillage (RT) intensity influenced invertebrates (such as rice pests and their predators), pathogens and weeds, that led to an impact on rice yield.This two year study showed that major rice pests, common diseases, and the density of weeds declined or were controlled by RT. The diversity and richness of pest predators increased in rice fields where RT or NT was used and yields increased gradually. The authors conclude that RT is beneficial for the protection of rice from various pests, and improves the sustainability of the agroecosystem and rice yield in southern China.

This paper reports on the use of "Push Pull Technology" (PPT) in maize that they use to control insect pests (stemborer) and parasitic weeds (Striga) in low fertility soils using two farming practices -- CT and CA - in Malawi. Stemborer and Striga infestations were investigated and the suitability levels of two Desmodium species as cover crops. Farmers' perceptions of PPT were gathered through a focus group discussion. The performance of PPT varied significantly between treatments, sites, and years on grain yields and the number of cobs that could be assigned to soil attributes. Results reaffirmed the technology's agronomic benefits in productivity, pest management, plant vigour, and Striga control. The cost of labour was described as a challenge, and research to identify more suitable Desmodium species is needed. They emphasized the importance of Desmodium and Brachiaria as animal fodder to improve the adoption of the technology.

This is an interesting paper on pest/disease issues of smallholder farmers in Sub-Saharan Africa, especially plant parasitic nematodes (PPN). Present control strategies in this part of Africa are therapeutic and unsustainable. What is needed are strategies that promote soil health and enhance suppression of PPN's. This review analyzes the potential impact of CA and Integrated soil fertility  management (ISFM) on PPN communities and it also provides a concise summary of low-cost PPN control strategies and their efficiency against specific nematode species. Variations in their efficacy is also discussed. 

This paper looks at the impact of agricultural intensification on arthropods, especially ground-dwelling predators that are negatively affected by tillage. They hypothesize that reducing soil disturbances conserves arthropod populations in the field and reduces the for chemical pest controls. They used pitfall traps in cereal fields with CT, Reduced tillage (RT) and NT under CA management. Overall, the activity-density of ground-dwelling predators was higher in fields with minimum soil disturbance and generally declined with increased distance to semi-natural habitats. Body size of beetles was also larger with less disturbance. The results obtained in the present study show that soil disturbances significantly influence arthropod abundance and diversity.

This is an interesting article on ground beetles that are an important component of biodiversity in agro-ecosystems as predators of pests and consumers of weed seeds. Unfortunately, there has been a gradual decline in these insects in Europe. This study looks at the impact of different tillage practices including NT on these beetles. They conclude on balance across multiple studies, greater tillage intensity tends to have a negative effect on abundance, species richness, and diversity of these beetles. The high variability of carabid responses to tillage is also a consequence of various modifying factors such as cover cropping, rotations, and variations in weed control associated with tillage. The paper has a good set of conclusions on this complex question that is worth reading.

This article assesses the effect of rotation in Northern European spring wheat (SW) cropping systems yield, pest and soil health using different tillage methods in a 12-year experiment in Finland. 3 crop rotations were used -- monoculture SW; a two year rotation with SW-rape-SW-barley; and a 4 year rotation SW-rape-barley-pea. Results show a diversified crop rotation improved SW yield by up to 30% in no-tillage and by 13% under plowing compared with monoculture. The yield quantity and quality differences between crop rotations were higher in no-tillage plots than in plowed plots. Weed species in SW before herbicide control was highest in the four-year crop rotation and lowest in the wheat monoculture. For plant diseases, wheat leaf blotch disease severity was lowest in the most diverse crop rotation when wheat was grown every 4th year.. Stem and root diseases became apparent after 6 years of rotation and the disease index was lowest in the most diverse crop rotation. Neither rotation nor tillage affected the control need of wheat midge. Based on our results, diverse crop rotations including cereals, oilseed crops, and legumes increase yield and reduce plant disease severity of spring wheat in Finland, with the magnitude being larger in no-tillage system

This is an interesting article from India on the impact of CA on insect pests and their natural enemies in wheat in the rice-wheat system of the Western Indo-Gangetic Plains. Major insect pests (foliar aphids, root aphids, termites, and pink stem borer) and their natural enemies in wheat managed under three tillage practices, i.e., zero-till (ZT), reduced tillage (RT), and conventional tillage (CT) with (protected) and without (unprotected) insecticide protection scenarios, was investigated. Foliar aphids and termites were lowest in the ZT-protected treatments and highest in the CT-unprotected system. Root aphids were highest in the reduced tillage-unprotected system. More fine-tuning of insect-pest management tactics based on these relations would enhance the success of CA systems. 

This paper looks at the effect of cropping systems on larger macrofauna. They sampled 21 fields in France that were used for conventional, conservation or organic systems, either long-established (≥ 7 years) or in transition (≤ 3 years). Tillage, pesticide treatment and organic matter input intensity were assessed in each field. Macrofauna density and diversity, earthworm ecological categories, species richness and functional traits were investigated. They report that density and diversity showed few differences in respect to cropping systems with high variation across years and groups. They conclude that more information is needed on actual cropping systems in order to better assess the impacts of cropping systems on biodiversity.

This paper has created a database using 218 response variables from the following 5 common categories of CA from the Mid-Western USA from 1980-2020: cover crops, tillage management, pest management, nutrient management, and crop diversification. The data was collected from the Web of Science. They also have summarized all this data on a web site, https://www.agevidence.org/

They conclude that this web site and database will be useful for the many stakeholders involved in making decisions on how to make more food with less environmental impact.

This paper looked at western corn rootworm (WCR) interactions with the soil microbiome are affected by a CA system - corn-soybean-wheat rotation with cover crops under no-till compared to a more traditional system - corn-soybean under mulch tillage and no cover crops when combined with transgenic Bt corn. They applied soil microbes from each system to two corn lines, one Bt and one non-Bt. They then reared Bt=-resistant and Bt susceptible WCR on inoculated seedlings to look at plant and insect changes in fitness. Bt was effective against susceptible larvae in both crop systems. However, Bt-resistant larvae were 20% smaller when reared where soil microbes came from CA systems. Comparing the microbial communities using 16S rRNA sequencing revealed that management practices influenced the microbiomes associated with the soil and the plant rhizosphere, but not WCR. They suggest that the value to  growers utilizing conservation management practices, is by bottom-up changes to plant–insect interactions via the soil microbiome.

This review of articles from 2000-2020 looks at the importance and current research status of crop rotation in agriculture. Note this is an important third pillar in CA. Five knowledge domains were identified as important for rotations (a) synergism and comparison of conservation agriculture measures or other management measures; (b) soil microecology, pest control, weed control, and plant disease control; (c) soil carbon sequestration and greenhouse gases (GHGs) emissions; (d) organic crop rotation and double cropping patterns; and (e) soil properties and crop productivity. In addition six important research areas were identified -  (a) plant–soil microbial interactions; (b) integrated effect with minimum soil disturbance and crop retention; (c) carbon sequestration and GHG emission reduction; (d) impact on weed control; (e) heterogeneity of rotation effects under different weather and soil conditions; and (f) comparison between long-term and short-term rotation.

This study looked at the effects of rotation (determines residue type) and tillage (affects residue load and distribution) on residue decomposition and wheat yield. Crop rotations in long-term trials in this region consisted of wheat–medics, lupin–wheat–canola–wheat, canola–wheat–lupin–wheat, and wheat monoculture. Tillage treatments were CT (chisel plow plus soil inversion with tine planter); MT (chisel plow and tine planter); NT (direct drilling with tine planter); and ZT (direct drilling with a double disc planter). Results showed no effect on residue decomposition, but increased wheat LAI and yield when rotated with medics, lupin and canola compared to monoculture. ZT increased residue load and improved seedling establishment. NT and ZT increased residue decomposition compared to CT with less soil disturbance..

This paper from Australia looks at stubble born cereal diseases related to adoption of CA. The fungal pathogens that cause these diseases can saprotrophically colonise retained cereal residues, which may further increase inoculum levels post-harvest. The study looked at 3 stubble borne fungal pathogen sand compared under a range of moisture regimes of six cereals varieties - 2 wheat and barley and 1 durum and oat. Saprotrophic colonisation also increased with increasing relative humidity for all pathogens and varied by cereal type. They concluded that reduced cereal harvest height, may limit saprotrophic colonisation and improve stubble-borne disease management in conservation agriculture systems.

This paper evaluated the importance of the third principle of CA, crop rotation and diversification to control weeds, pests, and diseases that can lead to increased yields and profits in Brazil. The objectives of this study were to determine whether grain production systems that employ crop rotation with species diversification are more productive and profitable than double-cropping rotations without diversification and to analyze the revenues and production costs of these cropping systems over a five year period, all under no-tillage and maize-soybeans. They conclude that where crop rotation was used there was higher productivity and profit than maize-soybean systems with rotation.

This paper looks at various impacts on water of various sustainable agricultural measures. Straw retention and reduced tillage were mentioned as the most successful measures in arid and semi-arid regions. As such this review looks at these two factors in respect of SOM, soil moisture, soil temperature, soil microorganisms, soil enzyme activity, soil fertility, soil carbon emissions, pests, weeds, soil erosion, water use efficiency and yield under different tillage systems. Straw mulching increased SOM, soil moisture and reduced drought, but can increase pest and diseases and change the microbial community. But straw mulch does enhance WUE and yield. Reducing tillage maintained soil integrity, which is conducive to soil and water conservation.

This is an interesting paper that looks at rotations, one of the pillars of CA in Brazil. Recently rotation has been changed to crop diversity. The most common cropping pattern in Brazil is soybean/second corn crop succession and has led to problems with water and soil conservation and increase in pests and diseases and thus increase in energy use. This study looked at 6 different cropping patterns compared against the one above. Both the traditional and alternate cropping patters provided positive energy balance and efficiency -- they produced more energy than they consumed. But some of the newer systems had higher energy balances and efficiency than the traditional one. The abstract did not mention any differences in pests and diseases though but may have in the paper.

This review discusses the potential of soil and crop management practices such as minimum/reduced/no-tillage, use of organic manure, balanced and integrated plant nutrient application, precision land leveling, precision water and pest management, residue management, and cropping system optimization to maintain the C-equilibrium between soil and atmosphere and to enhance the C-sequestration in the long run. Results of meta-analysis show a potential 36% increase in soil organic C stock in the top 0–15 cm layer in this region. The authors conclude that there is an urgent need for scaling up and accelerated adoption climate resilient technologies to increase soil C-sequestration. Policies and programs need to be devised for incentivizing farmers to adopt more C-neutral or C-positive agricultural practices.

This study looks at the impact of long-term CA production systems under rice-based cropping systems on pest status. In this study, direct and indirect effects of tillage (zero, reduced and conventional tillage), residue retention and cropping sequences on abundance and damage by pests were investigated. After 4–5 years of experimentation, populations of oriental armyworm in wheat, mealybug and bandicoot rat in rice were found to increase abnormally in CA-based production systems. Conventionally tilled plots had a significant negative effect while residue load in zero-tilled plots had a significant positive effect on larval population build-up of armyworm. Based on the present study, pest management strategies in CA need to be revisited with respect to tillage, residue retention on soil surface, grassy weeds in the field and cropping sequences to deliver the full benefits of CA in MIGP to achieve the sustainable development goals under the climate change scenarios.

This is another interesting article of surface dwelling beetles that are important for biological pest control and organic matter decomposition. It looks at the beetle community responses to 6-years of tillage, crop residue use, rotation and soil fertility amendments. Reduced tillage increased beetle abundance  compared to inversion tillage. Crop residue also increased the incidence of some beetle species by 2-3 times. Another beetle increased by 628.6% in high fertilizer compared to manure + 60 kg N ha−1, manure + low fertilizer and the control. They conclude that reduced tillage, retention of crop residues on the soil surface and application of manure increase surface-dwelling beetle abundance and diversity.