Cropping diversity with rice influences soil aggregate formation and nutrient storage under different tillage systems

• Published in: Journal of plant nutrition and soil science 2021-02, Vol.184 (1), p.150-162
• Main Authors: Jahangir, Mohammad M. R., Jahiruddin, Muhammad, Akter, Hasina, Pervin, Rahana, Islam, Khandakar Rafiq
• Format: Article
• Language: English
• Subjects: aggregate stability; Aggregates; Brassica; Brassica napus; Continuous cropping; Crop production; Diameters; Environmental degradation; Environmental quality; Lens culinaris; mean weight diameter; Mustard; nutrient sequestration; Nutrients; Organic carbon; Organic soils; Oryza sativa; Rice; Soil degradation; Soil fertility; Soil properties; Soil stability; system productivity; Tillage; Triticum aestivum; Wheat
• ISSN: 1436-8730; 1522-2624
• DOI: 10.1002/jpln.202000310

Background: The soils under continuous rice monocropping are currently facing a serious threat of accelerated soil and environmental quality degradation. Aims: Examining the impact of tillage and cropping diversity on soil aggregate stability and associated nutrients in a sub‐tropical rice ecosystem. Methods: A split‐plot experiment with tillage (minimum, MT vs. conventional, CT) as a main plot and cropping diversity [mustard (Brassica napus)–rice (Oryza sativa)–rice (M–R–R), wheat (Triticum aestivum)–rice–rice (W–R–R), and lentil (Lens esculenta)–rice–rice (L–R–R)] as a sub‐plot was repeated for four years. Soil aggregate properties were measured using wet sieving techniques. Soil organic carbon (SOC) and nutrients were measured in different aggregate size groups as well as in the bulk soil samples. Results: Results show that all the aggregate size groups were similar in both MT and CT, except in 0.85–0.30 mm. Likewise, cropping diversities increased soil aggregation, being higher aggregate size of < 0.053 mm in M–R–R relative to the W–R–R and L–R–R, where the latter two were alike. By contrast, > 2 mm aggregates were higher in L–R–R than in M–R–R and W–R–R, where the latter two were similar. The MT increased aggregate mean weight diameter (MWD) by 14% in W–R–R, and by 29% in L–R–R. Soil organic carbon (SOC), total N (TN), and available P were higher in MT than in CT, while it was alike for exchangeable K and available S. While W–R–R had a higher aggregate‐associated SOC, available P, and available S, L–R–R had a higher TN, and M–R–R had a higher exchangeable K. While SOC, TN, and exchangeable K accumulated more in the > 0.85 mm size aggregates, the available P, in contrast, accumulated more in