Organic Amendments and Reduced Tillage Accelerate Harvestable C Biomass and Soil C Sequestration in Rice–Wheat Rotation in a Semi-Arid Environment

Abstract

Rice–wheat crop rotations have high carbon fluxes. A 2-year field study in Punjab, Pakistan quantified impacts of different nutrient management on harvestable carbon biomass, crop-derived C, soil organic C sequestration (SCS), and decomposition. Treatments included different combinations of mineral fertilizer, animal manure (20 Mg ha−1), and incorporated crop residue in a split-plot design under conventional tillage (CT) and reduced tillage (RT). Combined use of mineral fertilizer and manure resulted in (1) 12.56% to 53.31% more harvestable C biomass compared to use of fertilizer and manure alone and (2) 18.27% to 60.72% more crop-derived C inputs relative to using only fertilizer or manure across both tillage practices. Combined fertilizer/manure treatments also significantly enhanced SCS relative to using fertilizer alone. Using only manure increased SCS by 63.25% compared with fertilizer alone across both tillage practices. The relationship between SCS and C inputs indicated high humification (14.50%) and decomposition rates (0.46 Mg ha−1 year−1) under CT compared to RT at 0–15 cm soil depth. At 15–30 cm soil depth, rates of humification (10.7%) and decomposition (0.06 Mg ha−1 year−1) were lower for CT compared to RT. Combined manure/fertilizer treatments could induce high C sequestration and harvestable C biomass with reduced decomposition in rice–wheat rotations.

Evaluating the Impact of Pre-Anthesis Water Deficit on Yield and Yield Components in Triticale (X <i>Triticosecale</i> Wittmak) Genotypes under Controlled Environmental Conditions

“…Breeders are interested in finding stable genotypes with broad adaptation possibilities, especially those concerning yield and quality (Goyal et al, 2011). As the loss of the thousand grain weight was lower under stresses, crop productivity would be maintained (Duggan et al, 2000;Shaukat et al, 2023). The non-significant genotype and environment interaction (for most traits except for days to anthesis and peduncle diameter) in the present study correspond to the fact that all genotypes respond similarly to stress treatments.…”

Predicting Soil Carbon Sequestration and Harvestable C-Biomass of Rice and Wheat by DNDC Model

“…A two-year field study was carried out at the agronomic research station of the University of Agriculture in Faisalabad, Pakistan to study the effects of organic and mineral fertilization on soil organic carbon sequestration and harvestable C-biomass in a rice-wheat rotation. Detailed information about the experimental setup, crop management, measurement methods, and soil analysis is available in Shaukat et al [24]. Tillage systems during the rice season and the wheat season were the (1) conventional tillage (CT) treatment (two cultivations with a tractor-drawn cultivator along with one rotavator pass followed by planking for rice, and three cultivations along with one rotavator pass followed by planking for wheat) and the (2) reduced tillage (RT) treatment (one cultivation along with one rotavator for both crops).…”

“…About 6000 kg ha −1 of rice straw was applied. This experiment started with the sowing of wheat, and rice stubbles already collected were cut into 3 cm sections [24] and returned to the field. After the harvest of wheat, wheat stubble yield under the RT NPK treatment (n = 3) was calculated, and this ranged from 5500 to 6500 kg ha −1 .…”