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In rainfed Mediterranean environments crop yields are limited by nitrogen (N) and water. The concept of water and N co-limitation has been used to describe how these competing resources are allocated during growth, it has been proposed that growth is optimum when water and N are equally limiting. All the published work so far on water and N co-limitation has been done in cereals using single applications of fixed amounts of N. However, delayed and split applications of N at key phenological growth stages can improve N use efficiency and alter the severity of N and water stress during the growth of the crop. The aim of the work reported here was to assess water and N co-limitation in the indeterminate crops canola ( Brassica napus ) and mustard ( B. juncea ) under different post-sowing N treatments. Four field experiments were conducted over three years with different cultivars of canola and mustard, under different water regimes, and grown with three N rates (0, 100 and 200 kg N ha −1 as granular urea) applied at different phenological growth stages. The results suggested that yield gaps (Y g ; the difference between actual and attainable yield) increased as total stress from water and N ( T WN ) and the maximum of the two stresses ( M WN ) increased and declined as the degree of water-N co-limitation increased, whether based on total stress ( CT WN ) or maximum stress ( CM WN ). However, seasonal and genotypic variation in the Y g reduction and improvement in water use efficiency (WUE) with the degree of co-limitation were observed for CT WN . Application of N improved the CT WN without having the effect of split N application timing. No relationship was found between N use efficiency for seed yield (NUE SY ) of canola and mustard and co-limitation indices, which may be due to low N uptake efficiency during the pre-flowering period and low physiological efficiency during the post – flowering period. This study provides the first empirical evidence that yield of canola and mustard is co-limited by water and N under post-sowing N application with seasonal and genotypic variation in response to CT WN . Future studies need to focus on the interaction of pre and post-flowering water and N stresses and their effect on CT WN in devising crop management tools for this environment. [ABSTRACT FROM AUTHOR]

Canola has a high nitrogen requirement and optimal nitrogen (N) management in environments with variable rainfall is a challenge. This study investigated the impact of timing of N as a single or split application at different growth stages on seed yield, N uptake and water-use efficiency in canola. Nitrogen rates of 100 and 200 kg ha−1 were applied after sowing when two leaves were unfolded or equally split between the rosette, green bud and first flower stages. The experiments were conducted at two sites with contrasting rainfall and a supplementary irrigation treatment at the low rainfall site, generating a third environment. Nitrogen application increased seed yield by up to 20% at a high rainfall site and by up to 77% at a medium rainfall site, but the timing of N did not significantly affect the yield response to N. Seed yield was closely associated with total dry matter production and seed m−2. N-use efficiency was influenced more by N recovery and uptake efficiency, rather than physiological efficiency, which highlights the importance of soil moisture availability and the ability of the crop to exploit soil water and N reserves. The results suggest that better use of subsoil moisture by overcoming some of the subsoil constraints may be an avenue for further improvements in yield and nitrogen-use efficiency (NUE) of canola in this environment. [ABSTRACT FROM AUTHOR]

Quinoa belongs to the family Chenopodiaceae, a pseudo‐grain having high nutritional value and is considered an underexploited vegetable crop with the potential to improve the nutritional security of millions. Therefore, assessing genetic diversity in Chenopodium germplasm to untap nutritional and site‐specific adaptation potential would be of prime importance for breeders/researchers. The present study used 10 accessions of two Chenopodium species, that is, C. quinoa and C. album. Quantitative and qualitative phenotypic traits, proximate composition, minerals, and amino acids profiles were studied to compare the differences in nutritional value and extent of genetic diversity between these two species. Our results showed significant variation existed in yield attributing agro‐morphological traits. All the traits were considered for hierarchical clustering and principal components analysis. Large genetic variability was observed in traits of Chenopodium accessions. The protein, dietary fiber, oil, and sugar content ranged from 16.6% to 19.7%, 16.8% to 26%, 3.54% to 8.46%, and 3.74% to 5.64%, respectively. The results showed that C. album and C. quinoa seeds had good nutritional value and health‐promoting benefits. The C. quinoa was slightly ahead of than C. album in terms of nutritional value, but C. album accession IC415477 was at par for higher test weight, seed yield (117.02 g/plant), and other nutritional parameters with C. quinoa accessions. IC415477 and other potential accessions observed in this study may be taken up by breeders/researchers in the near future to dissect nutritional value of Chenopodium and related species for dietary diversity, which is imperative for the nutritional security of the ever‐growing world's population. [ABSTRACT FROM AUTHOR]

The global outbreak of SARS-CoV-2 has spurred a reassessment of Municipal Solid Waste management strategies and approaches. A significant need for sanitation and hygiene was accentuated for disease prevention and control with the onset of the pandemic. With an alteration of the status quo in waste management system, an unprecedented amount of face masks, protective equipment, and other biological wastes was generated in the form of Municipal Solid Waste . This upsurge of potentially infected wastes originated a risk of transmission amongst frontline workers. Furthermore, the potential contamination of Municipal Solid Waste was rendered as a legitimate threat due to improper collection practices, disposal and handling of solid waste. Several novel waste disposal techniques and waste management policies were also introduced during this period. However, the sanitation-policy making-occupational safety nexus remains inadequately explored under the prevalent COVID-19 scenario. Through the prism of shifting waste composition, this review offers a global assessment of existing solid waste management systems during the COVID-19 pandemic. The physiological and psychological hazards faced by the frontline workers were explored and instances of best-case and worst-case policies on solid waste handling were recorded. Modern methods of waste disposal and latest trends of policymaking were evaluated. A model study of unsupervised learning via Partition Around Medoids cluster analysis was undertaken to reveal underlying patterns of waste management policies. Although, the clusters were formed devoid of any socio-economic parameters, this study strives to indicate proof of concept and can serve as a precursor to advanced clustering studies. [ABSTRACT FROM AUTHOR]

Soils present a limited resource for agricultural production and bear a vast diversity of organisms crucial for crop health and the provision of ecosystem services. There is growing evidence that agricultural practices affect soil microbial community structure and function but currently, there is a knowledge gap when it comes to tropical arable farming systems. In this study, we investigated the long-term impact of organic and conventional production systems on bacterial communities in two field trial located on a rhodic and humic nitisol in the Central Highlands of Kenya. The field sites operate on a full factorial design, testing farming systems (organic vs conventional) and input levels (high vs low). Including four field replication we assessed soil bacterial community structure via amplicon sequencing of the 16S rRNA gene and soils capacity for nitrification and nitrous oxide reduction via qPCR of functional genes (bacterial and archaeal amoA , nosZ) after 12 years of distinct management and before the start of the 5th three-year crop rotation period in 2019. The abundances of amoA bearing nitrifiers and nosZ bearing nitrous oxide reducers were enhanced in the high input organic production system on humic but not in rhodic nitisols. For both soil types, high input organic production system resulted in distinct bacterial community structure with enhanced bacterial richness compared to conventional and low input production systems. In rhodic and humic nitisols 160 and 84 OTUs were found to be indicative for organic production system at high input levels organic. Taxa associated with this system were identified as potential primary decomposers or symbionts related to plant nitrogen fixation, suggesting organic fertilization strategies such as manure composting as major driver for changes in soil bacterial community structure. This study reveals that organic production systems at high input levels on tropical nitisols translates to distinct soil bacterial communities with increased capacity for soil processes that are crucial for crop nutrient supply. • Distinct soil bacterial communities in organic systems in humic and rhodic nitisols • Increased bacterial richness in high input organic systems in humic nitisols • High-input organic farming raises nitrification capacity in humic nitisols. • Lifestyle of indicative taxa mainly linked with organic matter decomposition [ABSTRACT FROM AUTHOR]

An extensive stratified survey was conducted in two different wheat growing seasons in all districts of Haryana (India) to evaluate current agronomic practices and assess performance in wheat production with the purpose of identifying where farmers can make further changes in practices. The survey involved 116 villages (927 farmers) in 2008 and 103 villages (823 farmers) in 2010. Different sized farming operations from each village were surveyed to represent all socio-economic categories of farmers. Agronomic inputs (tillage method, fertilizer practice, variety choice, time of sowing, irrigation, and rotation practice) and yield data are presented as mean data, and individual farmer's information is represented by regression tree (RT) analysis to highlight primary associations between cropping management and wheat yield and the technical efficiency (TE) measure. TE was calculated using the key agronomic variables obtained from the survey, and the farms with the highest TE values were assessed as having the superior ‘best practice’ technology. In the districts where the rice–wheat rotation was adopted, there was an overall higher level of TE. Where rice–wheat rotation is the main cropping practice (for example in Kaithal and Kurukshetra), many of the farmers have adopted zero tillage farming methods, with one third of farmers in Kaithal using zero tillage for planting wheat. In contrast, in Sirsa district where cotton was favoured by the farmers as their monsoon season crop, there were no farms where zero tillage was practised. Also, there was also no zero tillage farming where the pearl millet/cluster bean rotation was used as the monsoon season crop. In most cases farmers use a two applications of nitrogen fertilizer applied post-emergence, particularly in the rice–wheat and cotton–wheat districts. The survey also showed that application of potassium fertilizer and use of zinc is regionally specific and this is consistent with the soil maps that show the potential for deficiency of these nutrients in Haryana districts. Sowing in the rice–wheat districts was mostly at the recommended time in early November. The highest number of irrigations occurred in the districts using the pearl millet–wheat and cluster bean–wheat rotations where sprinkler irrigation is the main application practice. The analysis of TE provides a useful comparison when the 5 different farm size categories are separated. There was no difference in TE with farm size, suggesting the message concerning best practice for wheat production is available to and adopted by farmers irrespective of scale of operation. This analysis highlights where extension messages could be focused, whether for zero tillage in the non-rice districts, management of macro-nutrients, or the targeted use of micronutrients. [ABSTRACT FROM AUTHOR]