Exploring suitable maize straw-return measures is essential for the new double-cropping system of maize (Zea mays L.)–rice (Oryza sativa L.) rotation in the middle reaches of Yangtze River in China, which can increase crop yield by improving soil quality. In this study, four straw-return measures were evaluated by investigating the soil bulk density (BD), organic matter (OM), microbial community, and nutrients from 2016 to 2018. The four straw-return treatments were as follows: (1) no straw-return (CK), (2) only rice straw incorporated into the field (M₀R_i), (3) both maize and rice straw incorporated to field (M_iR_i), and (4) maize straw mulched and rice straw incorporated into the field (M_mR_i). Compared to CK, two-season crop straw-return treatments changed soil microbial community composition, and increased soil total organic carbon (TOC) and dissolved organic carbon (DOC), microbial biomass carbon (MBC), mineralized nitrogen (N_min), available phosphorus (P) and exchangeable potassium (K) in the 0–20 cm soil layer by 3.6%, 63.4%, 38.8%, 12.4%, 39.7%, and 21.6%, respectively, averaged across M_mR_i and M_iR_i treatments. In addition, M_mR_i and M_iR_i increased annual yield by 9.1% and 15.2% in 2017 and 11.7% and 12.9% compared to CK in 2018, respectively. M_mR_i exhibited superiority in the soil microbial community, enzyme activities, DOC, MBC, N_min, available P, and exchangeable K in contrast to M_iR_i. We concluded that M_mR_i is the best measure to implement for straw-return in maize–rice rotation systems.

High temperature during May to July is a major hurdle for production of sorghum as fodder in Pakistan, ultimately resulting in a deficit with respect to the demand of meat and milk for increasing population. A field study was conducted to investigate the impact of exogenous application of natural plant growth-promoting substances on forage yield and quality of sorghum. Seed priming and foliar application (alone or in combination) with 1% sorghum water extract (SWE), 3% moringa leaf extract (MLE) and water were applied. Two foliar applications, the first at one month after sowing and the second at 45 days after sowing were carried out. Untreated seeds were used as control. The results indicated that priming and foliar spray performed best in combination as compared to priming or foliar application alone. All MLE applications (priming plus foliar application, priming alone, foliar spray alone) enhanced growth parameters and chlorophyll contents, which ultimately improved forage yield and total dry matter production of sorghum plants. An increase in crude protein and total ash and decrease in crude fiber was also recorded in plants treated with MLE. The results of this study revealed that exogenous application of MLE at 3% concentration (priming plus foliar application, priming alone, foliar spray alone) significantly enhanced the yield through improvement in sorghum growth.

Arbuscular mycorrhizal fungi (AMF) substantially enhance soil fertility and are widely recognized as one of the most extensively researched biological inoculants. However, the effects of AMF on soil nutrient availability in mango orchards, along with the physiological processes regulating this availability under varying soil fertility conditions, remain poorly understood. To address this research gap, experiments were conducted with two soil types (soil from mango orchards co-cultivated with butterfly pea plants for 5 years) and a control (no butterfly pea plants) and two mycorrhizal inoculations (+AMF and –AMF). Rhizophagus irregularis was used as the mycorrhizal inoculum. These experiments examined the physicochemical properties, microbial community composition, and metabolic profiles in mango orchard soils by integrating high-throughput sequencing with soil metabolomics. In nutrient-poor soils, the introduction of AMF enhanced the occurrence of specific bacterial species and elevated the richness and diversity of the soil bacterial community. This enhancement subsequently increased the activities of soil enzymes such as cellulase, β-glucosidase, chitinase, and nitrate reductase in mycorrhizosphere soil, leading to improved soil pH, and increases in soil microbial biomass carbon (MBC), ammonium nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃⁻-N), available potassium (K), and available phosphorus (P). Furthermore, alterations in soil properties and metabolites restructured the soil microbial community, with pH and MBC emerging as the key factors shaping bacterial distribution within mycorrhizosphere soil co-occurrence networks. In contrast, the effects of AMF on soil nutrient availability were weaker in high-fertility soils. We conclude that AMF enhance soil nutrient availability in mango orchards by regulating soil bacterial community structures, particularly in low-fertility soils.