Conservation Agriculture Research Updates - March 2026

This paper from South Africa looks at the production performance, soil greenhouse gas emissions, and soil carbon sequestration of different crop rotations. They measured nitrous oxide and methane fluxes over one year and analyzed 20 years of historical data on soil carbon sequestration, yields, fertilizer use, and wheat protein content. Results showed that rotations that contained legumes and livestock produced more wheat and canola yields and higher wheat protein. All systems showed an increase in SOC over the 20 year period. They concluded that "Legumes and livestock incorporation in crop rotations interact with nitrogen management. Most N2O emissions occurred after precipitation in the otherwise dry summer, making reduction difficult as minimal management activities occur over this fallow period.

This paper from Bangladesh had two 5-year field experiments on two different soils to measure the effects of CA on soil microbial populations. The first, on non-calcareous soils had two tillage; minimal (MT) and conventional (CT), three cropping patterns involving rice-rice with lentil, wheat and mustard LRR, WRR and MRR, and plus and minus residue. The second experiment on calcareous soil had three tillage; strip-till (ST), NT and CT and two previous crop residue treatments - High (50%) and Low (15%). Non-calcareous soils had higher fungal populations with higher microbial biomass carbon but lower nematode and bacterial populations compared to the calcareous soils. In non-calcareous soils, MT had higher microbial populations than C at 0-7.5cm but no difference below that. LRR had more microbial populations then MRR and WRR. In the calcareous soil, NT and ST had higher microbial populations than CT. the more residue left on the surface resulted in higher microbial populations.

This paper evaluates GHG emission, global warming potential (GWP), GHG intensity and net SOC variations in rice-mustard-rice cropping systems under CT and strip tillage (ST) on-station. The ST reduced methane (CH4) CH4 flux, GHG intensity and GWP than CT in rice. In mustard ST reduced GHG intensity and GWP compared to CT. There was about 33% increase in N2O emission and 24% augmentation of soil respiratory CO2 with ST compared to CT. There was a 10%  rice equivalent yield increase in ST compared to CT. They conclude that ST can minimize soil C loss, improve net ecosystem CO2 absorption, and reduce GHG intensity and GWP under the rice-mustard-rice system.

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 investigates the effects on no-till (NT) and shallow conservation tillage (RT) in combination with cover crop mixtures in rotations with at least three different crops in on-farm experiments in Germany. Experiments were done in 18 farms and 2 experiment stations over 6 years. Yields of cereals, oilseed rape, maize, soybean and peas were slightly lower under no-tillage than under conservation tillage. Cover cropping did not affect crop yields. Tillage and cover cropping had no influence on weed control in the subsequent main crop. They conclude that CA with minimum tillage had slight advantages compared to the no-till system under their farming conditions.

This paper looks at biological soil quality in the IGP of India in rice-based cropping looking at tillage and residue management. The objectives of this study were to determine the effect of seasonal variation on enzyme activity and assessing biological soil quality (BSQ) under conservation agriculture (CA)-based rice-mustard cropping. They collected soil samples in the 9th year from two soil depths and looked at biological attributes. They found that the CA-based NT systems with rice-mungbean-mustard with residues had the best biological attributes and recommend this system in India