Conservation Agriculture Research Updates - March 2026

CA is being used in this coastal area of the USA to improve soil health, reduce environmental impacts, and improve farmer profits. They commonly use cover crops, strip, minimal, and no tillage. The paper evaluates the changes in soil properties from various CA  practices. They evaluated 4 tillage systems: conventional, strip, minimal, and no-tillage; 3 winter cover crop systems; fallow, winter cash crop, and high biomass CC. They then measured 6 soil properties over 7 years. Altogether, soil carbon showed a more consistent response to conservation management than the other soil properties, which tended to show greater variability based on the time since tillage. They conclude that conservation practices need to be applied for multiple years in order to improve soil properties. 

Tillage and residue retention influence carbon storage within soil aggregates and particulate organic matter. This paper studied the effect of CA involving NT with surface residue mulch (NTM) in a maize-wheat system on particulate (POC) and mineral associated organic C (MinOC), C storage within aggregates and acid non-hydrolysable C (NHC) in a sandy loam soil and compared NTM to conventional tillage without residue. Results showed that the NTM improved SOC stocks by 23% more than CT in the 0-15cm. The results also showed that the effects of NTM were brought about by improved aggregate stability and C preservation inside macroaggregates of size >1 mm. They conclude that CA and NT plus residue leads to SOC sequestration in coarse textured soils. 

This paper collected undisturbed soil cores from the FArming System and Tillage long-term field experiment (FAST) near Zurich (Switzerland) to compare conventional. organic, and conservation agriculture systems for soil structure and physical conditions. This site has been under these 3 systems since 2009. The assessed 28 soil chemical and physical properties and related them to root growth, microbial biomass and bacteria and fungi diversity. They conclude that each management system creates contrasting soil physical environments. It also highlights the trade-off between creating a facilitative environment for root growth by tillage and maintaining complex and diverse soil microhabitats for microbes under conservation agriculture.

This paper evaluated the effect of CA management - no-till rice straw mulching on soil health parameters including SOC in the inter-rows of two citrus orchards in Spain. Various soil physical, chemical, and biological  were studied in the top soil layer (0-20cm) over 3 years. Their results showed that rice straw mulch resulted in reduced soil temperature that then resulted in higher crop root growth and increased soil macrofauna development and higher soil enzyme activities. The rice mulch also increased soil macroporosity and SOC levels showing that it enhances soil health in citrus orchards in Spain. However, compacted soils, the beneficial effects of straw mulching on soil health were still limited after three years of treatment.

This field experiment from India looked at the effects of nitrogen (N) and residual sulphur (S) on maize in the 11th year of a long term CA maize-mustard system. CA (3) was NT maize with mustard residue + brown manuring (not described in the paper) and NT mustard with maize residue had the highest maize height and dry weight than other CA and CT treatments except CA (4) that had mungbean residue for the NT maize that had similar height and dry weight. The 100% and 75% recommended dose of N gave comparable grain yield under all CA-based treatments, indicating a saving of 25% N compared to CT. The sulphur applied to mustard did not show any residual effect on maize grain. They conclude that the CA framework enhances yield and incomein a maize-mustard system.

This paper looked at how NT and cover cropping influences SOC and soil respiration (SR) at two sites with different soil carbon in SW France. Two adjoining maize fields with one using NT + CC, and another with CT were used. No differences were observed at the 0-90cm depth in the initial high SOC content site. In the lower SOC site the NT+CC treatment had higher SOC at the 0-90cm depth and respiration than the CT treatment. The NT+CC conservation treatments also had a positive effect on the SOC at the upper layers and deeper layers. They conclude that the ability of NT+CC to sequester large amounts of SOC leading to mitigation of GHG emissions depends on the initial SOC contents.

This study looks at the combined effects of straw mulching (+ and -) and tillage methods (no-tillage, rotary tillage, and plow tillage) on soil water, N, root distribution, plant N nutrition, tiller capability, and grain yield of dryland maize-wheat. Straw mulching with no-tillage showed higher soil moisture, mineral N, and Olsen-P content, and increased root length and surface area (in the 0-20cm but not the 20-40cm soil layer) compared to no-mulch with rotary tillage or plow tillage. Straw mulching with no-tillage showed greater above ground plant dry mass and shoot N%, leading to increased plant N nutrition, tillering capability, and grain yield. The recommend maize straw mulching with no-tillage for dryland farming communities to replace the rotary tillage conventional system.

This study used continuous maize without straw retention (C) as a check to compare with 3 other systems -- 1) continuous maize with straw retention (CS); 2) maize-peanut rotation (R); and 3) maize-peanut with straw retention (RS). Straw retention (CS) increased soil total organic carbon (TOC), active organic carbon (AOC) and microbial biomass carbon (MBC) but did not increase maize yield. Treatments R and RS increased dissolved organic carbon (DOC) in the rhizosphere by promoting root growth and also increased maize yield. For the microbial community structure, PERMANOVA and PCoA indicated that the bacterial community differed significantly between rhizosphere soil and bulk soil, but the fungal community shifted more under different agricultural practices. They conclude that ensuring plant root development and improving root-bacteria interactions are of great importance to guarantee crop yield when implementing conservation tillage practices.

This 6-year study examined the residual effect of tillage and nutrient management applied to summer rice on root growth-attributes and impact on morpho-physiology of succeeding winter pea  grown uniformly under NT. Increased root exudation was observed under NT and MT (minimum till) along with organic residue addition. Also, enhanced chlorophyll pigmentation and favourable leaf characteristics were observed in the pea crop grown under NT with 50% NPK+weed biomass (WB)/green leaf manure (GLM) applications. They conclude that adoption of MT/NT along with 50% NPK+WB/GLM in summer rice is recommended for inducing favourable root environment and optimised pea production in succeeding winter season in study region of the Eastern Himalayas,

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 study was initiated since traditional irrigation systems in the region are suffering from water scarcity. This study looks at sub-surface drip-irrigation (SSDI) and fertigation systems to increase irrigation water efficiency and water productivity, root systems and soil water balance in cotton–wheat cropping systems (CWCS). Results show that SSDI enhanced root systems and showed more secondary roots and root length in cotton and wheat. This also resulted in about 43% water saving compared to flood irrigation. Fertigation through the SSDI resulted in a 20% reduction in fertilizer needs. This SSDI system is now being promoted in dryland areas of the region that need irrigation to grow crops.They are also promoting CA practices that use no-till and residue mulch to improve soil properties.

This paper from Lithuania looks at the relationship between root network development and CO2 emission as affected by different cropping and tillage strategies. They tested 5 different cropping systems with or without cover crops (CC) using different tillage practices. Results showed that with no-till (NT) C02 emission was higher than in conventional tillage (CT). Increase in CO2 emission also varied between 30 and 35% depending on the share of legume and CC inclusion. Root growth and development were significantly affected  by soil depth and cropping strategies in terms of root length and root volume changes. The inclusion of CC resulted in a decrease in root volume. Root length and root volume had a significant impact on soil CO2 emissions. They concluded that crop diversification and addition of CC helped reduce C02 emissions and improved root networks better than monocropping.

This paper looks at better rooting systems of wheat genotypes under CA. They do this by screening wheat genotypes under hydroponic conditions. The explored root traits of 55 Synthetic Hexaploid Wheats (SHW) and 19 bread wheat cultivars developed over the past 100 years in India. They found substantial root diversity among the wheat lines. Analysis of a subset of 34 SHW lines revealed that some had greater root lengths, root volumes, root surface area, and number of root tips when compared to bread wheat popular varieties. In CA, coleoptile thickness is equally important as coleoptile length because it helps the crop emerge well from the high residue load. They conclude that further research is needed to identify better CA wheat material.

No-tillage (NTR) with residual plastic mulch is being adopted in arid regions of China to reduce plastic residue, soil disturbance, and improve water use efficiency (WUE). They compared conventional tillage (CTN) and NTN with new plastic mulch with those of 1,2 and 3 years of NTR on soil physical, soil water, maize root and shoot growth, yield, and economic benefits. They showed that the longer duration of NTN and NTR, the higher the bulk density and lower soil porosity compared to CTN in the 0-30 cm depth. Read the paper for more results. They conclude that NTR for 2 years can be recommended and help reduce the problem of plastic residue while increasing economic benefits.

This paper looks at the effects of ridge-furrow plastic film mulch (RFPM), a widely adopted conservation agricultural practice, on root system morphological traits, root exudation processes, the rhizoplane microbiota, and their connections compared to conventional practices. RFPM enhanced root growth, altered root exudate profiles, and changed the rhizoplane microbiota. Details are available in the paper. They conclude that RFPM causes changes in the rhizoplane microbiota, affecting microbial substrate utilization and physiological adaptation, and highlights the role of root exudation in mediating colonization of rhizoplane-root system niches by the root-associated microbiota in response to conservation agricultural practices.

This paper investigates the root system dynamics of summer mung bean under different conservation agriculture practices. The best root properties were recorded in the Soybean (permanent bed; PB)-Wheat(PB)-Summer mung (PB)(+Residual; +R) based cropping systems, followed by Maize(PB)-Wheat(PB)-Summer mung (PB)(+R), while, the lowest values of above parameters were recorded in the Puddled Transplanted Rice-Conventional till (PTR-CT) Wheat-Summer mung (-R). The mung yields and yield components were also the highest in the Soybean-wheat-mungbean system listed above. The yield of summer mung bean increased when residues were retained. They conclude that the inclusion of summer mung in soybean-based cropping systems may substantially improve the root architecture and soil quality and increase crop yield under conservation agriculture.

This paper looks at the use of CA to help overcome the problems associated with Meloidogyne and Hirschmanniella the most damaging plant-parasitic nematodes (PPNs) in rice production in Asia. Thery investigated the effects of two components in Cambodia (i) CA practices, no-tillage with a cover crop Stylosanthes guianensis, versus conventional plow-based tillage with no cover crop. Under CA, the abundance of PPNs extracted from the roots was reduced by 88%. Soil quality was also improved that provided more basal resources for beneficial microbes. They conclude thier study confirms that CA is an alternative to nematicides to limit infection by PPNs in rice cropping systems.