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Ghana, being blessed with abundant solar resources, has strategically invested in solar photovoltaic (PV) technologies to diversify its energy mix and reduce the environmental impacts of traditional energy technologies. The 50 MW solar PV installation by the Bui Power Authority (BPA) exemplifies the nation's dedication to utilizing clean energy for sustainable growth. This study seeks to close the knowledge gap by providing a detailed analysis of the system's performance under different weather conditions, particularly on days with abundant sunshine and those with cloudy skies. The research consists of one year's worth of monitoring data for the climatic conditions at the facility and AC energy output fed into the grid. These data were used to analyze PV performance on each month's sunniest and cloudiest days. The goal is to aid in predicting the system's output over the next 365 days based on the system design and weather forecast and identify opportunities for system optimization to improve grid dependability. The results show that the total amount of AC energy output fed into the grid each month on the sunniest day varies between 229.3 MWh in December and 278.0 MWh in November, while the total amount of AC energy output fed into the grid each month on the cloudiest day varies between 16.1 MWh in August and 192.8 MWh in February. Also, the percentage variation in energy produced between the sunniest and cloudiest days within a month ranges from 16.9% (December) to 94.1% (August). The reference and system yield analyses showed that the PV plant has a high conversion efficiency of 91.3%; however, only the sunniest and overcast days had an efficiency of 38% and 92%, respectively. The BPA plant's performance can be enhanced by using this analysis to identify erratic power generation on sunny days and schedule timely maintenance to keep the plant's performance from deteriorating. Optimizing a solar PV system's design, installation, and operation can significantly improve its AC energy output, performance ratio, and capacity factor on sunny and cloudy days. The study reveals the necessity of hydropower backup during cloudy days, enabling BPA to calculate the required hydropower for a consistent grid supply. Being able to predict the daily output of the system allows BPA to optimize dispatch strategies and determine the most efficient mix of solar and hydropower. It also assists BPA in identifying areas of the solar facility that require optimization to improve grid reliability. [ABSTRACT FROM AUTHOR]

Ghana, being blessed with abundant solar resources, has strategically invested in solar photovoltaic (PV) technologies to diversify its energy mix and reduce the environmental impacts of traditional energy technologies. The 50 MW solar PV installation by the Bui Power Authority (BPA) exemplifies the nation’s dedication to utilizing clean energy for sustainable growth. This study seeks to close the knowledge gap by providing a detailed analysis of the system’s performance under different weather conditions, particularly on days with abundant sunshine and those with cloudy skies. The research consists of one year’s worth of monitoring data for the climatic conditions at the facility and AC energy output fed into the grid. These data were used to analyze PV performance on each month’s sunniest and cloudiest days. The goal is to aid in predicting the system’s output over the next 365 days based on the system design and weather forecast and identify opportunities for system optimization to improve grid dependability. The results show that the total amount of AC energy output fed into the grid each month on the sunniest day varies between 229.3 MWh in December and 278.0 MWh in November, while the total amount of AC energy output fed into the grid each month on the cloudiest day varies between 16.1 MWh in August and 192.8 MWh in February. Also, the percentage variation in energy produced between the sunniest and cloudiest days within a month ranges from 16.9% (December) to 94.1% (August). The reference and system yield analyses showed that the PV plant has a high conversion efficiency of 91.3%; however, only the sunniest and overcast days had an efficiency of 38% and 92%, respectively. The BPA plant’s performance can be enhanced by using this analysis to identify erratic power generation on sunny days and schedule timely maintenance to keep the plant’s performance from deteriorating. Optimizing a solar PV system’s design, installation, and operation can significantly improve its AC energy output, performance ratio, and capacity factor on sunny and cloudy days. The study reveals the necessity of hydropower backup during cloudy days, enabling BPA to calculate the required hydropower for a consistent grid supply. Being able to predict the daily output of the system allows BPA to optimize dispatch strategies and determine the most efficient mix of solar and hydropower. It also assists BPA in identifying areas of the solar facility that require optimization to improve grid reliability.

Intensive rice-based systems are mining soil potassium (K) due to negative K balances. Conservation Agriculture (CA) practices may increase yield and economic return of rice-based systems but there is limited understanding of their effects on K pools and balances. This study evaluated crop productivity and K input–output balances under contrasting rice-based intensive cropping and long-term CA. The comprised three factors- (a) soil disturbance (strip planting, SP and conventional tillage, CT); (b) residue retention (low, LR, 20 cm by plant height and high, HR, 50 cm) and; (c) K application-100% K (recommended dose, RD), 50–75% K of RD (low dose, LD), and 125–150% K of RD (high dose, HD). The long-term experiment initiated in 2010 and soil samples were collected in 2018 after 24th crop and 2020 after 30th crop of triple cropping system. The K balances for the 2018 cropping cycle were negative, ranging from − 47 to − 82 kg ha−1 yr−1. In the 2020 cycle, when the high K dose was increased from 125 to 150% of RD, the negative K balance was significantly reduced in SP-HR-HD (− 19 kg ha−1 yr−1) while 23–35% higher cropping system yield was achieved. Leaching was a significant K loss pathway. Overall results indicate that minimum soil disturbance and increased crop residue retention had significant positive effects on cropping system yield and K balance. However, to achieve neutral K balance in intensive rice-based cropping systems, increased recycling of K from crop residue, higher doses of K addition or lower K losses are needed. [ABSTRACT FROM AUTHOR]

• The study focuses on examining different PCMs to be used in PVT systems. • Hybrid PCMs were produced from mixing Vaseline and paraffin. • Vaseline mixes with paraffin and reduces its melting point. • Lower melting point of the PCM corresponds to an increase in the heat flow rate. • Best cooling results were obtained when using the hybrid PCM. The use of phase change materials (PCMs) in photovoltaic-thermal systems (PVT) is essential for developing PV systems and raising their productivity. PCM is distinguished by its many variations and properties, the most important of which is the melting point. In this study, the driven question and focus was on investigating which is better for use in a PVT, PCM systems with a high or low melting point? Two types of PCM were used in the study: paraffin wax (melting point 45 °C), Vaseline -petroleum jelly (melting point of 25 °C), and hybrid PCM (mixtures of the two PCMs in proportions of 25%, 50% and 75%). The study was conducted indoors by simulating the harshest condition in Iraq's weather in summer. The results showed that the wax and the Vaseline mixed entirely with an apparent decrease in the product's melting point. In contrast, the rest of the thermophysical properties of the product were relatively affected. The use of paraffin, petroleum jelly and 50% paraffin + 50% Vaseline in the PVT system caused a decrease in the surface temperatures of the photovoltaic cell, which resulted in a more significant improvement in the performance of the system. The maximum electrical efficiency reached was 13.7%, while the maximum thermal efficiency was 39.0%. Reducing paraffin melting point leads to better performance of PVT systems, as the hybrid paraffin (50% wax + 50% Vaseline) have better productivity than pure paraffin wax due to its lower melting point. [ABSTRACT FROM AUTHOR]

Productivity and economics of different rabi crop-based systems were evaluated at farmers' field in Durgapur upazilla of Rajshahi district, Bangladesh to select the best rabi crop(s) for fitting in the T. Aman rice - rabi crop - DDS Aus rice pattern. Nine rabi crops namely, (1) Mustard, (2) Potato, (3) Lentil, (4) Field pea, (5) Radish, (6) Cabbage, (7) French bean, (8) Carrot and (9) Tomato were cultivated during the rabi season in between the two rice crops to form nine cropping patterns. The experiment used Randomized Complete Block Design (RCBD) with three replications. Aman rice variety BRRI dhan57 was transplanted on 12 July 2017 and harvested on 28 October 2017, while, Aus rice variety BRRI dhan28 was sown in the dry cultivated land on 16 March 2018 and harvested on 24 June 2018 while rabi crops were sown/transplanted on 28 November 2017. Proper agronomic management practices were adopted for all the crops in the patterns. Data on yield and related attributes of DDS Aus rice were recorded at harvest. In addition, the yield of Aman rice and all the rabi crops were recorded. In addition, rice equivalent yield of each rabi crop, system yield (total yield of all the crops in the sequence), cost of production, gross return and benefit cost ratios (BCR) of all the patterns were recorded. Results revealed that yield of dry direct seeded Aus rice cv. BRRI dhan28 did not differ significantly due to different rabi crops grown under the respective patterns. The system yield was the highest in T. Aman rice -tomato - DDS Aus rice pattern (19.62 t ha-1) and the lowest with T. Aman rice -mustard - Aus rice pattern (14.63 t ha-1). Since the market price of a rabi crop changes from year to year, the net profit of a pattern depends on the yield of a crop grown in rabi season. Therefore, any of the nine rabi crops under the trial can be successfully cultivated in between the two rice crops under Aman rice - rabi crop -Aus rice patterns. However, the present study concludes that any of the nine rabi crops can be grown in between the two rice crops but carrot, French bean, mustard, field pea, and tomato could be the most profitable ones for the T. Aman rice - rabi crops -DDS Aus rice patterns. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the effect of sowing methods and deficit irrigation on weed dynamics, yield and water-use efficiency (WUE) of the maize–cowpea system during the summer and monsoon seasons, respectively. The field experiment was carried out for two years (2015 and 2016) using a split design with three replicates under irrigated (maize) and rainfed (cowpea) conditions on vertisols of a semi-arid region. Treatments included three sowing methods [i.e., broad bed and furrow (BBF), corrugated furrow (CF) and ridges and furrow (RF)] and four irrigation levels [i.e., irrigation once in 10 days (I10D), irrigation at 40% (I40), at 50% (I50) and at 60% (I60) depletion]. The results indicated that, regardless of weed flora (monocots, dicots and sedges), the RF method produced higher weed density (2.09–2.98 No. m−2) compared to CF (2.00–2.80 No. m−2) and BBF (1.85–2.64 No. m−2) in maize at 30 and 60 days after sowing (DAS). The RF method with irrigation at I40 and I50 recorded significantly higher weed density, followed by the CF and BBF method. A similar trend was also observed with dry weight of weeds (monocot; 24.19%, dicot; 25.52%, and sedges; 29.80%) in maize at 30 and 60 DAS. Higher weed density and dry weight of weeds in the RF method with I40 was due to higher soil moisture availability and higher nutrient uptake due to larger lateral wetting of the soil and greater water use (29.27%). However, the BBF method favoured the growth of weeds (9.33–16.60%) in cowpea at 55 DAS and coped under rain-fed situation over CF and RF. The CF with moderate depletion (I50) method produced significantly higher maize equivalent yield (MEY) of cowpea (10,000 kg ha−1) with considerable reduction in the total water usage (19.33%). Therefore, under a water scarcity situation, growers can practice CF and I50 for higher yield and WUE of maize–cowpea sequence cropping.

A key motivation for managing invasive alien plant (IAP) species is their impacts on streamflows, which, for the wetter half of South Africa, are about 970 m³∙ha−1∙a−1 or 1 444 mill. m³∙a−1 (2.9% of naturalised mean annual runoff), comparable to forest plantations. However, the implications of these reductions for the reliability of yields from large water supply systems are less well known. The impacts on yields from the WCWSS were modelled under three invasion scenarios: ‘Baseline’ invasions; increased invasions by 2045 under ‘No management’; and under ‘Effective control’ (i.e. minimal invasions). Monthly streamflow reductions (SFRs) by invasions were simulated using the Pitman rainfall−runoff catchment model, with taxon-specific mean annual and low-flow SFR factors for dryland (upland) invasions and crop factors for riparian invasions. These streamflow reduction sequences were input into the WCWSS yield model and the model was run in stochastic mode for the three scenarios. The 98% assured total system yields were predicted to be ±580 million m³∙a−1 under ‘Effective control’, compared with ±542 million m³∙a−1 under ‘Baseline’ invasions and ±450 mill. m³∙a−1 in 45 years’ time with ‘No management’. The ‘Baseline’ invasions already reduce the yield by 38 mill. m³∙a−1 (two thirds of the capacity of the Wemmershoek Dam) and, in 45 years’ time with no clearing, the reductions would increase to 130 mill. m³∙a−1 (capacity of the Berg River Dam). Therefore IAP-related SFRs can have significant impacts on the yields of large, complex water supply systems. A key reason for this substantial impact on yields is that all the catchments in the WCWSS are invaded, and the invasions are increasing. Invasions also will cost more to clear in the future. So, the best option for all the water-users in the WCWSS is a combined effort to clear the catchments and protect their least expensive source of water. [ABSTRACT FROM AUTHOR]

Abstract Farmers expect yield reduction of cash crops like cocoa when growing in agroforestry systems compared to monocultures, due to competition for resources, e.g. nutrients and water. However, complementarities between species in the use of resources may improve resource use efficiency and result in higher system performance. Cocoa trees have a shallow rooting system while the rooting characteristics of the associated trees are mainly unknown. This work investigates fine root distribution and production in five cocoa production systems: two monocultures and two agroforestry systems under conventional and organic farming, and a successional agroforestry system. In the organic systems a perennial leguminous cover crop was planted and compost was added, while herbicides and chemical fertilizers were applied in the conventional ones. We measured cocoa fine root parameters in the top 10 cm of soil and annual total fine root production at 0–25 and 25–50 cm depth. We related the root data with both the aboveground performance (tree and herbaceous biomass), and the cocoa and system yields. Cocoa fine roots were homogenously distributed over the plot area. Around 80% of the total fine roots were located in the upper 25 cm of soil. The total fine root production was 4-times higher in the agroforestry systems and the organic monoculture than in the conventional monoculture. The roots of the associated tree species were located in the same soil space as the cocoa roots and, in principle, competed for the same soil resources. The cocoa yield was lower in the agroforestry systems, but the additional crops generated a higher system yield and aboveground biomass than the conventional cocoa monocultures, implying effective resource exploitation. The leguminous cover crop in the organic monoculture competed with the cocoa trees for nutrients, which may explain the lower cocoa yield in this system in contrast with the conventional monoculture. Graphical abstract Unlabelled Image Highlights • Fine roots are concentrated in the topsoil implying competition between species. • Cocoa fine root parameters were not affected by species interactions. • Belowground competition reduces cocoa growth and yield in agroforests. • Agroforests have higher system yield and biomass than monocultures. [ABSTRACT FROM AUTHOR]

Highlights • Balanced use of nutrients through STCR based fertilizers with organic manures recorded increasing trend of yield. • Sole use of chemicals or organics could not sustain the yield and system productivity of maize- chickpea system. • Long-term integrated use of organic and inorganic sources of nutrients enhanced the system productivity and soil health. Abstract Long-term sustainability concerns are growing in agriculture owing to over and under application of fertilizers and poor management of available resources which are resulting into soil health deterioration and declining crop productivity. Balanced and integrated use of organic and inorganic fertilizers is the most logical concept for managing and sustaining long term soil health and crop productivity. Hence, a long-term field experiment was conducted from 2012 to 2017 to develop integrated nutrient management (INM) practices for sustaining crop productivity and maintaining soil health under maize (Zea mays L.) chickpea (Cicer arietinum L.) cropping system in Vertisols of central India. Twelve treatments that comprised of various combinations of general recommended dose (GRD) of NPK, farmyard manure (FYM), poultry manure (poultry manure), urban compost (UC), maize residue (MR), glyricidia loppings (GL) and soil test crop response (STCR) based NPK with target yield 5.0 and 1.50 Mg ha1 in maize and chickpea, respectively were tested. The experiment was conducted following a Randomized Complete Block Design (RCBD) set up with three replications and Simple Random Sampling (SRS) technique of sampling. The results indicated that the grain yield and system yield were observed to be significantly higher with 75% NPK of STCR + FYM at 5 Mg ha1 treatment and recorded an increase of 20.9% and 13.08% in mean grain yield of maize and chickpea, respectively over GRD. The combined analysis results illustrated significant (P < 0.0001) year x nutrient management interaction effect on grain yield with N input (R2 = 0.80) and N uptake (R2 = 0.91). Stepwise multiple regression model also showed that the N input and N uptake significantly (P < 0.05) influenced the system yield under different INM practices. However, apparent nutrient balance was negative for N and K in all treatments except higher level of FYM treatment (FYM at 20 Mg ha1) while P balance was positive under balanced and complete nutrition through organic and inorganic treatments over the years. A significant increase was observed in the various soil health indicators (physical, chemical and biological) under balanced and integrated use of organic and inorganic fertilizers. FYM, poultry manure and urban compost improved the physical properties of soil like mean weight diameter (MWD), water stable aggregates (WSA), bulk density and porosity. The application of higher level of FYM (20 Mg ha1) significantly increased the soil organic carbon (SOC) (6.30 g kg1), SOC stock (11.8 Mg ha1), carbon sequestration rate (213.1 kg ha1 year1), KMnO 4 -N (121.7 mg kg–1), Olsen-P (23.8 mg kg–1) and NH 4 OAc-K (273.5 mg kg–1) concentration in surface soil as compared to GRD and control treatments. The soil enzymes, dehydrogenase (DHA), alkaline phosphates (Alk-P) and fluorescein diacetate (FDA) were enhanced significantly with the application of FYM at 20 Mg ha1 and STCR based 75% NPK + FYM at 5 Mg ha1. The STCR based 75% NPK along with FYM at 5 Mg ha1 treatment recorded highest sustainable yield index (SYI) 0.84 and 0.92 with maximum guaranteed yield of 6.19 and 1.99 Mg ha1 in maize and chickpea, respectively. The results indicate that the chickpea yield was more sustainable as compared to the maize. [ABSTRACT FROM AUTHOR]

Scientific knowledge, societal debates, and industry commitments around sustainable cocoa are increasing. Cocoa agroforestry systems are supposed to improve the sustainability of cocoa production. However, their combined agronomic, ecological, and socio-economic performance compared to monocultures is still largely unknown. Here we present a meta-analysis of 52 articles that directly compared cocoa agroforestry systems and monocultures. Using an inductive, multi-dimensional approach, we analyzed the differences in cocoa and total system yield, economic performance, soil chemical and physical properties, incidence of pests and diseases, potential for climate change mitigation and adaptation, and biodiversity conservation. Cocoa agroforestry systems outcompeted monocultures in most indicators. Cocoa yields in agroforestry systems were 25% lower than in monocultures, but total system yields were about ten times higher, contributing to food security and diversified incomes. This finding was supported by a similar profitability of both production systems. Cocoa agroforestry contributed to climate change mitigation by storing 2.5 times more carbon and to adaptation by lowering mean temperatures and buffering temperature extremes. We found no significant differences in relation to the main soil parameters. The effect of the type of production system on disease incidence depended on the fungal species. The few available studies comparing biodiversity showed a higher biodiversity in cocoa agroforestry systems. Increased and specific knowledge on local tree selections and local socio-economic and environmental conditions, as well as building and enabling alternative markets for agroforestry products, could contribute to further adoption and sustainability of cocoa agroforestry systems.

Water resource system behaviour is commonly evaluated using Monte Carlo simulation of synthetic streamflow and rainfall data. Fundamental to this process is the estimation of stochastic model parameters by calibration to short observed records. The uncertainty in key hydroclimate parameters, such as the mean, variance and serial autocorrelation, flows through to the simulated hydroclimate data. This study considers the subsequent influence of model parameter uncertainty on the calculated yield of a case study water supply system. A procedure is developed to estimate the system yield for individual samples of model parameters, providing a probability distribution of plausible system yields. The uncertainty in hydroclimate parameters is found to have an appreciable impact on the uncertainty in system yield - of the order of +/−10%. This uncertainty is likely to surpass, potentially by an order of magnitude or more, the influence of many choices made by water managers in both the modelling and operation of water resource systems. [ABSTRACT FROM AUTHOR]

Evaluation of genetic materials bred in monoculture can provide only limited information about the potential to improve crops for the intercrop environment. Selection in intercrop may be required to uncover the genetic variability associated with intercrop adaptation. Due to the expense and difficulty associated with selection in the intercrop environment, its use must be justified by the superiority of materials selected in it over materials selected in monoculture. The aim of this study was to compare the improvement of overall performance in corn-bean (Zea mays L.-Phaseolus vulgaris L.) intercrop that resulted from intercrop selection, with that which resulted from selection in monoculture, Three cycles of divergent recurrent selection were used to generate two sets of improved corn families: YM selected for corn yield in monoculture and YS selected for system yield (corn yield plus three times bean yield) in corn-bean intercrop. YS allowed significantly (P < 0.01) higher bean yield and had higher system yield than YM. YS was also significantly shorter (P < 0.05), less leafy (P < 0.001), and had a more erect canopy (P < 0.05) than YM. Selection for system yield in intercrop uncovered adaptation to the intercrop environment that was not matched by selection for corn yield in monoculture. This justifies the use of the intercrop breeding environment for improvement of productivity from corn-bean intercrops. [ABSTRACT FROM AUTHOR]

Different integrated crop management (ICM) modules have been developed to enhance the productivity and profitability of the rice-wheat rotation (RWR) of the upper Indo-Gangetic Plains (IGPs). As the available options are used quite often singly or with the few combinations, hence in the present study, eight ICM modules have been evaluated; wherein, ICM 1&2 - conventional transplanted rice fb flatbed wheat, ICM 3&4 - conventional direct seeded rice (DSR) fb furrow irrigated raised bed wheat without residues, ICM 5&6 - conservation agriculture (CA)-based modules [zero tilled (ZT) DSR and ZT wheat] with the wheat and rice residues, and ICM 7&8- CA-based modules (ZTDSR and ZT wheat) with the wheat, mungbean and rice residues. Results revealed that ICM 8 produced the highest mean rice grain yield, which was statistically similar to ICM 1&7 , however it was 10.1–20.7% greater than the ICM 2–6 modules. Similarly, the ICM 7 recorded 14–16% greater wheat grain yield than the ICM 1–6 (five years' mean), but it was at par to the ICM 8. Furthermore, the ICM 7&8 produced 10–13% (5 years av.) higher system yields in terms of rice equivalents over the ICM 1&2. Water use (WU) was the highest in ICM 1&2 and was 8–12% higher than the ICM 3–8. In contrast, the highest water productivity (WP) was recorded with the ICM 7&8 , wherein it was14–16% greater than the ICM 1&2. The ICM 1&2 had incurred the highest variable production costs (US$ 912–1105 ha−1 yr−1), followed by ICM 7&8 (US$ 856–1021 ha−1 yr−1). Nevertheless, on an average, the ICM 7&8 gave 19–22% additional returns than the ICM 1&2. Also, the ICM modules had a significant (p < 0.05) and positive impact on the soil carbon (0.0–0.45 m). The CA-based (ICM 5–8) residue retained modules registered a 10–25% greater total OC stock than the ICM 1–4 in 0.0–0.45 m soil layer. The current study thus up-holds the importance of adequate inputs integration, and hence, adoption of the CA-based ICM in the RWR improved the soil carbon dynamics, crop yields, farm profits, besides water savings of the upper Indo-Gangetic Plains (IGPs) of north-west India. • ZTDSR-ZT wheat (ICM 7&8) had a positive impact on the system yields (10–13%) and farm economics (19–22%) than CT modules (ICM 1&2). • Residue retained ZTDSR-ZT wheat (ICM 5–8) contributed 12–17% greater total OC stock than the CT practices (ICM 1–4). • Modules ICM 5–8 saved 8–12% water and increased the system water productivity by14-16% than the CT rice and wheat (ICM 1&2). • Synergistic effects of ICM components reflected in complimenting the supply of nutrients besides conserving soil fertility. [ABSTRACT FROM AUTHOR]

• Intensification of the rice-wheat system increased system productivity. • CA further enhanced the baseline system though CA benefits are environment-specific. • In fine-textured soil (silt-loam), CA enhanced system productivity and resource use efficiency. • In course-textured soil (sandy-loam), the system benefit (productivity and resource use efficiency) of full CA seems limited. Increasing productivity of the rice-wheat system (RW) in the Eastern Gangetic Plains (EGP) is a major challenge in the context of the various economic (increasing cost of labour, irrigation water, and energy) and bio-physical (water scarcity, depletion of soil fertility, and climatic variability) constraints. We evaluated the performance of three RW system intensification options with different management interventions over two years, comparing a conventional RW rotation (CS 1), with two stages of conservation agriculture (CA) interventions, (i) the simple inclusion of mungbean (CS 2), and (ii) the inclusion of mungbean together with full CA implementation (CS 3) at two sites in the EGP that differed with respect to soil type, water table dynamics, and agro-climatic conditions. Our evaluation focussed on improving system productivity and resource use efficiency. The addition of mungbean into the conventional RW rotation produced significantly higher system productivity (rice equivalent yield, REY) compared with the existing double-crop rotation across sites. The baseline system was enhanced further when CA-based management practices were adopted, however, the magnitude of system benefit from CA was site and situation-specific. At the fine-textured soil site, gains were observed in system production (by 5.4 %), irrigation water productivity (WP I , by 40 %), and N use efficiency (NUE, by 5%) for the CA-based intensified system (CS 3) in comparison with the CT-based intensified system (CS 2). The average wheat yield and WP I in the zero-till (ZT) system (CS 3) was always higher than in the conventional (CT) systems (CS 1 and CS 2), mainly due to enhanced wheat rooting after unpuddled rice across the sites. At the fine-textured soil site, the cessation of puddling in rice cropping maintained rice grain yield, while increasing WP I. However, in the coarse-textured soil site, the cessation of puddling resulted in lower rice grain production (by 14 %), coupled with much higher (1.3 times) irrigation water requirement than the conventional puddled rice systems (CS 1 and CS 2) in the second year due to increased percolation rate, which negatively impacted the overall performance of the CA-based system (CS 3). Therefore, the modification of the traditional CT-based system to an intensified CA-based approach can improve the productivity of the RW system in terms of yield of the component crops as well as better NUE and WP I in fine-textured soil, while the feasibility of the full CA system in coarse-textured soil seems limited due to poor performance of rice, and requires further research focusing on the best rice establishment option. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the effect of sowing methods and deficit irrigation on weed dynamics, yield and water-use efficiency (WUE) of the maize–cowpea system during the summer and monsoon seasons, respectively. The field experiment was carried out for two years (2015 and 2016) using a split design with three replicates under irrigated (maize) and rainfed (cowpea) conditions on vertisols of a semi-arid region. Treatments included three sowing methods [i.e., broad bed and furrow (BBF), corrugated furrow (CF) and ridges and furrow (RF)] and four irrigation levels [i.e., irrigation once in 10 days (I10D), irrigation at 40% (I40), at 50% (I50) and at 60% (I60) depletion]. The results indicated that, regardless of weed flora (monocots, dicots and sedges), the RF method produced higher weed density (2.09–2.98 No. m−2) compared to CF (2.00–2.80 No. m−2) and BBF (1.85–2.64 No. m−2) in maize at 30 and 60 days after sowing (DAS). The RF method with irrigation at I40 and I50 recorded significantly higher weed density, followed by the CF and BBF method. A similar trend was also observed with dry weight of weeds (monocot; 24.19%, dicot; 25.52%, and sedges; 29.80%) in maize at 30 and 60 DAS. Higher weed density and dry weight of weeds in the RF method with I40 was due to higher soil moisture availability and higher nutrient uptake due to larger lateral wetting of the soil and greater water use (29.27%). However, the BBF method favoured the growth of weeds (9.33–16.60%) in cowpea at 55 DAS and coped under rain-fed situation over CF and RF. The CF with moderate depletion (I50) method produced significantly higher maize equivalent yield (MEY) of cowpea (10,000 kg ha−1) with considerable reduction in the total water usage (19.33%). Therefore, under a water scarcity situation, growers can practice CF and I50 for higher yield and WUE of maize–cowpea sequence cropping. [ABSTRACT FROM AUTHOR]