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Increasing soil organic matter (SOM) contents improve the resilience of productive soil for future sustainability particularly in poor soil (<1% SOM). This study sought to elucidate how tillage and N fertilizer sources affect soil bulk density, soil organic carbon (SOC) and soil total N (TN) in 0‐ to 20‐cm soil depth. Treatments included minimum till (MT), conventional till (CT), deep till (DT), and twelve N treatments (60 and 120 kg urea N ha−1, 10 and 20 Mg farmyard manure [FYM] ha−1, 10 Mg soybean residue [SR] ha−1 and their combinations along with a control). The experiment was designed in randomized complete block design with split plot arrangement. Soil bulk density increased for DT toward the end of the experiment than CT or MT. The sequestration rates of SOC of MT was 22% higher than DT. The FYM retuned more SOC than SR, however SR returned more TN than FYM. Application of FYM as well as SR sequestered more C than urea or control. Conclusively, SOC returned was increased with 10 Mg FYM ha−1 along with 30 kg urea N ha−1 but TN with 10 Mg SR ha−1 in CT plots. This practice can therefore increase soil quality and productivity, and thus is considered a sustainable approach for soils deficient in organic matter. Core Ideas Minimum tillage improved C stock than shallow or deep tillage. The addition of urea increased SOC contents in SR plots than FYM. C Stocks in FYM and SR fertilized plots was about 3‐ to 4‐fold greater than control. Soybean residue build N stock principally in less plowed plots.

Agricultural production enhancement has been realized by more consumption of fossil energy such as fertilizer and agrochemicals. However, the production provides the present human with sufficient and diversified commodities, but at the same time, deprives in some extent the resources from the future human as well. In the other hand, it is known that synthetic herbicides face worldwide threats to human's health and environment as well. Therefore, it is a great challenge for agricultural sustainable development. The current review has been focussed on various oilseed crop species which launch efficient allelopathic intervention, either with weeds or other crops. Crop allelopathic properties can make one species more persistent to a native species. Therefore, these crops are potentially harmful to both naturalized as well as agricultural settings. On the other side, allelopathic crops provide strong potential for the development of cultivars that are more highly weed suppressive in managed settings. It is possible to utilize companion plants that have no deleterious effect on neighbor crops and can be included in intercropping system, thus, a mean of contributing to agricultural sustainable development. In mixed culture, replacement method, wherein differing densities of a neighbor species are planted, has been used to study phytotoxic/competitive effects. So, to use alternative ways for weed suppression has become very crucial. Allelochemicals have the ability to create eco-friendly products for weed management, which is beneficial for agricultural sustainable development. Our present study assessed the potential of four oilseed crops for allelopathy on other crops and associated weeds.

High input costs combined with multiple management and material inputs have threatened cotton productivity. We hypothesize that this problem can be addressed by a single fertilization at flowering with late sowing in a moderately populated plant stand. Field experiments were conducted to evaluate the cotton biomass accumulation, phosphorus dynamics, and fiber quality under three planting densities (low, 3 × 10 4 ; moderate, 6 × 10 4 ; and dense, 9 × 10 4 ha −1 ) and two cultivars (Zhongmian-16 and J-4B). High planting density had 6.2 and 12.6% larger stems and fruiting nodes m −2 , while low density produced a 37.5 and 59.4% maximum height node ratio. Moderate density produced 26.4-15.5%, 24.7-12.6%, and 10.5-13.6% higher biomass accumulation rate at the peak bloom, boll set, and plant removal stages over low and high density in both years, respectively. J-4B produced a higher reproductive organs biomass yield when compared with Zhongmian-16 in both years. This higher biomass formation was due to both the higher average (0.8 V T kg·ha −1 ·d −1 ) and maximum (1.0 V M kg·ha −1 ·d −1 ) reproductive organ phosphorus uptake, respectively. Plants with low density had 5.3-18.5%, 9.5-15%, and 7.8-12.8% greater length, strength, and micronaire values over moderate and dense plants, respectively. Conclusively, moderate density with J-4B is a promising option for improved biomass, phosphorus acquisition, and fiber quality under a short season.Agronomy 2019, 9, 500 2 of 18 nitrogen [6], water availability [7], planting date, and planting density [8] are factors that induce changes in dry matter formation and affect reproductive organ biomass accumulation.Biomass distribution in cotton organs during the crop cycle are important determinants of final yield. In the early phases of cotton growth, greater partitioning of foliar tissues enables access to light, which promotes better establishment and provides the basis for fiber quantity and quality later in the season. Similarly, during later growth phases, an increase in the assimilate transport to the reproductive structures ensures better crop yield. Planting density coupled with the cultivar are considered the key drivers for cotton production [8,9]. Due to its indeterminate growth habit, a cotton plant may invest heavily in vegetative biomass under optimum growth conditions. An over-investment of the assimilate into the vegetative or reproductive organs in cotton plants could stimulate the abscission of leaves or fruits, respectively [10,11]. The aboveground biomass of a cotton plant at maturity is often less than the total biomass produced as the plant may shed old leaves and young fruits [8]. Remobilization of biomass to reproductive structure may further reduce the total biomass of vegetative organs during late reproductive growth. Assimilate allocation, and thus the growth rate of a plant organ, is controlled by various environmental and physiological factors [12]. Generally, dry biomass formation and partitioning into organs is measured primarily during certain phenolog...

The combined use of organic manure and chemical fertilizer (CF) is considered to be a good method for sustaining high crop yields and improving soil quality. We performed a field experiment in 2019 at the research station of Guanxi University, to investigate the effects of cattle manure (CM) and poultry manure (PM) combined with CF on soil physical and biochemical properties, rice dry matter (DM) and nitrogen (N) accumulation and grain yield. We also evaluated differences in pre-and post-anthesis DM and N accumulation and their contributions to grain yield. The experiment consisted of six treatments: no N fertilizer (T1), 100% CF (T2), 60% CM + 40% CF (T3), 30% CM + 70% CF (T4), 60% PM + 40% CF (T5), and 30% PM + 70% CF (T6). All CF and organic manure treatments provided a total N of 150 kg ha−1. Results showed that the treatment T6 increased leaf net photosynthetic rate (Pn) by 11% and 13%, chlorophyll content by 13% and 15%, total biomass by 9% and 11% and grain yield by 11% and 17% in the early and late season, respectively, compared with T2. Similarly, the integrated manure and CF treatments improved post-antheis DM accumulation and soil properties, such as bulk density, organic carbon, total N, microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) relative to the CF-only treatments. Interestingly, increases in post-anthesis DM and N accumulation were further supported by enhanced leaf Pn and activity of N-metabolizing enzyme during the grain-filling period. Improvement in Pn and N-metabolizing enzyme activity were due to mainly improved soil quality in the combined manure and synthetic fertilizer treatments. Redundancy analysis (RDA) showed a strong relationship between grain yield and soil properties, and a stronger relationship was noted with soil MBC and MBN. Conclusively, a combination of 30% N from PM or CM with 70% N from CF is a promising option for improving soil quality and rice yield.

Crop nutrient management is an essential component of any cropping system. With increasing concerns over environmental protection, improvement in fertilizer use efficiencies has become a prime goal in global agriculture system. Phosphorus (P) is one of the most important nutrients, and strategies are required to optimize its use in important arable crops like cotton (Gossypium hirsutum L.) that has great significance. Sustainable P use in crop production could significantly avoid environmental hazards resulting from over-P fertilization. Crop growth modeling has emerged as an effective tool to assess and predict the optimal nutrient requirements for different crops. In present study, Decision Support System for Agro-technology Transfer (DSSAT) sub-model CSM-CROPGRO-Cotton-P was evaluated to estimate the observed and simulated P use in two cotton cultivars grown at three P application rates under the semi-arid climate of southern Punjab, Pakistan. The results revealed that both the cultivars performed best at medium rate of P application (57 kg ha) in terms of days to anthesis, days to maturity, seed cotton yield, total dry matter production, and harvest index during 2013 and 2014. Cultivar FH-142 performed better than MNH-886 in terms of different yield components. There was a good agreement between observed and simulated days to anthesis (0 to 1 day), days to maturity (0 to 2 days), seed cotton yield, total dry matter, and harvest index with an error of -4.4 to 15%, 12-7.5%, and 13-9.5% in MNH-886 and for FH-142, 4-16%, 19-11%, and 16-8.3% for growing years 2013 and 2014, respectively. CROPGRO-Cotton-P would be a useful tool to forecast cotton yield under different levels of P in cotton production system of the semi-arid climate of Southern Punjab.

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Hydrological models are widely applied for simulating complex watershed processes and directly linking meteorological, topographical, land-use, and geological conditions. In this study, the Soil and Water Assessment Tool (SWAT) was calibrated at two monitoring stations, which improved model performance and increased the reliability of flow predictions in the Upper Xijiang River Basin. This study evaluated the potential impacts of climate change on the streamflow and water yield of the Upper Xijiang River Basin using Arc-SWAT. The model was calibrated (1991–1997) and validated (1998–2001) using the Sequential Uncertainty Fitting Algorithm (SUFI-2). Model calibration and validation suggest a good match between the measured and simulated monthly streamflow, indicating the applicability of the model for future daily streamflow predictions. Large negative changes of low flows are projected under future climate scenarios, exhibiting a 10% and 30% decrease in water yield over the watershed on a monthly scale. Overall, findings generally indicated that winter flows are expected to be affected the most, with a maximum impact during the January–April period, followed by the wet monsoon season in the May–September period. Water balance components of the Upper Xijiang River Basin are expected to change significantly due to the projected climate change that, in turn, will seriously affect the water resources and streamflow patterns in the future. Thus, critical problems, such as ground water shortages, drops in agricultural crop yield, and increases in domestic water demand are expected at the Xijiang River Basin.