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Salt stress is the most pernicious of the abiotic stresses in arid and semiarid areas, having an adverse impact on crop growth and yields. Soil salinization decreases agricultural land by 1–2% every year and thus decreases crop yield, affecting ecological and socio-economic outcomes. Due to the increasing population and urbanization, it is the demand of the time to utilize every inch of land. In salt-affected soils, plant growth is destructively affected by the osmotic stress, ion toxicity, oxidative stress, and generation of ethylene. Salinity also affects microbiological processes and biological properties of soil and causes shifts in the microbial communities. Application of plant growth promoting microbes (PGPMs) is one of the significant strategies that can reduce the adverse effect of salt stress in crops and promote plant growth through several mechanisms such as secretion of growth hormones, increase in nutrient uptake, nitrogen fixation and protection from diseases. In this review, we have discussed salt affected soils and also addressed their impact on plant growth. We have highlighted the different mitigation strategies of salt-tolerant plant growth-promoting microbes which are beneficial for the growth of plants. [ABSTRACT FROM AUTHOR]

Worldwide zinc deficiency in the soil under cereal production is a common problem affecting the yield and nutritional value of several crops. Bioaugmentation of soil zinc with zinc-solubilizing bacteria can be a promising option for increasing the zinc nutrition to crops. The objectives of the study were to evaluate Bacillus paramycoides for improving yield, zinc nutrition, and zinc availability in rice grown under sodicity stress caused by alkali water irrigation. Treatments included T1: control, T2: substrate, T3: Bacillus paramycoides, T4: control (T1) + zinc sulphate, T5: substrate (T2) + zinc sulphate, and T6: Bacillus paramycoides (T3) + zinc sulphate. Rice yield, zinc content, and uptake, and apparent zinc recovery were not altered by Bacillus paramycoides. The different fractions of zinc measured after 30 and 60 days after transplanting of the rice remain unaffected by the inoculation of Bacillus paramycoides. Further, an equal number of zinc-solubilizing bacteria present in the rice rhizosphere of control plots after 30 days of transplanting suggests the importance of the native rhizospheric microbiome in zinc nutrition. It is concluded that the application of Bacillus paramycoides in sodicity-stressed rice did not provided additional benefits in terms of zinc nutrition and yield. Further investigation will be required to improve the apparent zinc recovery of crops in those areas, where alkali water is continuously utilized for irrigation. [ABSTRACT FROM AUTHOR]

Salt-affected soils (SASs) are globally distributed especially in the arid and semi-arid regions of the world which highly affect the crop growth and productivity. The soil physico-chemical and biological properties largely vary with different types of SASs which trigger the crop yield, nutrient imbalance and soil quality. Therefore, to understand the changes in soil microbiology in relation to soil characteristics, a micro plot study was conducted to evaluate the impact of soil salinity/sodicity on physical, chemical properties at surface (0–15 cm) and subsurface (15–30 cm) soils in relation to soil microbial population, activities and functional diversity with focusing on community-level physiological profiling (CLPP) study. Five types of soils based on pH, electric conductivity (EC) and salt concentration maintained for last 25 years - highly saline, moderately saline, highly sodic, moderately sodic and normal were evaluated in micro plots to understand the changes in soil biological properties in relation to salt concentration. The results revealed that the highest value of pH s , EC e (EC of soil saturated paste extract), cation exchange capacity (CEC), exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR), anions and cations concentrations, bulk density (BD), infiltration rate (IR), penetration resistance (PR) were observed in highly saline and highly sodic soils at surface and subsurface soil layer. In surface and subsurface layers, organic carbon (0.67 and 0.52 %) and available N (110 and 195 kg ha−1) were found higher under normal soils than SASs (% OC: 0.20–0.34 and 0.17–0.38; available N: 75–80 and 47–77 kg ha−1), respectively. In relation to changes in soil physicochemical properties, average well color development (AWCD) was found highest with normal soils followed by moderately saline and moderately sodic soils and lowest was found in highly sodic soils at surface soils which indicates interference of salts in metabolic activities of microbes. The utilization of amino acids, amines, carboxylic acids, phenolic compounds and polymers was highest for normal soils followed by moderately saline and lowest was recorded for highly sodic soils. But AWCD for carbohydrates was highest in highly saline soils, followed by highly sodic soils in contrast to normal soil and lowest was found under moderately sodic soils. Shannon diversity index (H) and substrate richness (SR) were found higher (3.19 and 24.07) in normal soils than SASs. Similarly, effect of salt load was also reflected on less soil enzymatic activities such as dehydrogenase, aryl sulfatase, invertase, etc. under varying types of SASs. Thus, with the increasing salt load, chemical and physical properties of soils were found to deteriorate and directly affected the microbial population, activities and their diversity in soil. This study indicated that soil physico-chemical properties, functional diversity, population and community of microbes were highly influenced by nature of salts and their concentration that may affect the soil quality and crop yield. [Display omitted] • Salt concentration in soils affects their physico-chemical and biological properties. • High concentration of anions and cations alter enzyme activities, microbial population and substrate utilization pattern of microbes. • Utilization of amino acids, amines, carboxylic acids, phenolic compounds and polymers was highest for normal soils followed by moderately and highly SASs. • Average well colour development (AWCD) for carbohydrates was higher in high salt loaded soils than low salt loaded soils. [ABSTRACT FROM AUTHOR]

Monotonous rice-wheat cropping system with conventional management practices have resulted in declining soil quality and biota in addition to low input factor productivity and farmer’s profitability in western Indo-Gangetic plains (IGP) of India. Conservation agriculture (CA) based sustainable intensification (SI) is required to improve the soil quality while improving the productivity and profitability. A field experiment was conducted to evaluate the effects of CA based management practices such as zero tillage (ZT), direct seeding of rice (DSR), crop diversification, residue recycling and legume integration for SI in comparison to conventional management on soil quality and biota in cereal (rice and maize) based cropping systems. Fourteen treatments were included in which four treatments (T 1 –T 4 ) with rice–wheat and two treatments (T 11 –T 12 ) with maize-wheat system were based on conventional management, while six treatments (T 5 –T 10 ) with rice–wheat and two (T 13 –T 14 ) with maize-wheat were based on CA management practices. Conservation agriculture based SI of maize-wheat-mungbean (T 14 ) recorded lower soil bulk density (1.33 Mg m −3 ). Soil organic carbon (OC) was increased by 83% and 72% with CA based rice-wheat-mungbean (T 10 ) and maize-wheat-mungbean (T 14 ) system, respectively and it was at par with T 9 and T 12 compared to farmer’s practice (T 1 ) (4.6 g kg −1 ). Mean microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) were 213% and 293% higher with T 14 over T 1 (646 and 201 µg g −1 dry soil), respectively. However, T 10 recorded 117% and 171% higher MBC and MBN, respectively compared to T 1 . Dehydrogenase activity (DHA) and alkaline phosphatase activity (APA) were improved by 210% and 49% under T 14 ; 140% and 42% under T 10 compared to T 1 (180 µg TPF g −1 soil 24 h −1 and 144 µg p-nitrophenol g −1 h −1 ), respectively. Mean number of bacteria, fungi and actinomycetes were increased by 28%, 68%, 98% respectively, under T 14 relative to T 1 , and at par with T 12 and T 10 . Most abundant micro-arthropod group belonged to Collembola followed by Acari and Protura , irrespective of treatments. Higher soil quality index (SQI) was observed in T 10 (0.82), followed by T 14 and T 6 treatment (0.76). Sustainable intensification of rice and maize based systems (T 10 and T 14 ) recorded 39% higher system yield compared to T 1 (11.12 Mg ha −1 ). CA-based sustainable intensification of rice/maize systems improved soil quality and biota, hence resulted higher system yield in alluvial soils of IGP. Conservation agriculture based SI of maize-wheat-mungbean system was found to be the best alternative option than rice–wheat system to achieve sustainable productivity while improving the soil quality index (35%) and conservation of natural resources. [ABSTRACT FROM AUTHOR]

Continuous rice-wheat (RW) rotation with conventional agronomic practices has resulted in declining factor productivity and degrading soil resources. A farmer's participatory research trial was conducted in Karnal, India to evaluate 8 combinations of cropping systems, tillage, crop establishment method and residue management effects on key soil physico-chemical and biological properties. Treatments (T) 1–4 involved RW and 5–8 maize-wheat (MW) with conventional tillage (CT) and zero tillage (ZT) with (+ R) and without (− R) residue recycling. Residue was either incorporated (R i ) or mulched (R m ). Treatment 1 (RW/CT − R) had the highest bulk density (BD) (1.47 Mg m −3 ) and T8 (MW/ZT + R m ), the lowest (1.34 Mg m −3 ). After 3 years of cropping, soil accumulated more organic C in (a) MW (9.33 Mg ha −1 ) than RW (8.5 Mg ha −1 ), (b) ZT (9.25 Mg ha −1 ) than CT (8.58 Mg ha −1 ), and (c) + R (10.18 Mg ha −1 ) than –R (7.65 Mg ha −1 ). MW system with ZT and residue (T8: MW/ZT + R m ) registered 208, 263, 210 and 48% improvement in soil microbial biomass C (MBC) and N, dehydrogenase activity (DHA) and alkaline phosphatase activity (APA), whereas RW system in T4 (RW/ZT + R m ) registered 83, 81, 44 and 13%, respectively as compared with T1 (RW/CT − R), the business as usual scenario. Treatment 8 (MW/ZT + R m ) recorded the highest microbial population viz. bacteria, fungi and actinomycetes. The most abundant micro-arthropods present in the soil of experimental plot were Collembola, Acari and Protura which varied with treatments. Soil MBC, APA, BD and micro-arthropod population were identified as the key indicators and contributed significantly towards soil quality index (SQI). MW system with ZT and R m (T8) recorded the highest SQI (1.45) followed by T6 (1.34) and the lowest score (0.29) being in T1 (RW/CT − R). The SQI was higher by 90% in MW compared to RW, 22% in ZT compared to CT, and 100% in residue recycling compared with residue removal. System yield was strongly related to key soil quality indicators and also positively correlated with SQI. Longer-term studies are essential to realize maximal effects of improvements in soil health on crop yields. [ABSTRACT FROM AUTHOR]

In the rice-wheat system dominated belt of India (Indo-Gangetic plains; IGP), paddy leaves, about 8 to 9 t/ha of loose and anchored residue in the field, are mechanically harvested. Farmers prefer to burn this residue to clear the field for the timely preparation of conventional wheat sowing. Insitu degradation by autochthonous fungi can be a better option for the disposal of unwanted crop residues. Autochthonous fungi isolated from conservation agriculture-based crop management fields were screened and assessed for their residue degradation potential. Nineteen isolates were selected for detailed enzymatic analysis in submerged fermentation, responsible for lignocellulosic residue degradation. Out of these five fungal isolates RPW 1/3 (Aspergillus flavus), RPW 1/6 (Aspergillus terreus), RPW 1/9 (Aspergillus terreus), RPWM 2/2 (Penicillium janthinellum) and RZWM 3/1 (Aspergillus niger) showed higher activities of cellobiase, CMCase, FPase, xylanase, and laccase enzymes in solid state fermentation. Further two isolates RPW 1/3 and 1/6 showed approximately 30% degradation of straw residue after 10 days incubation. [ABSTRACT FROM AUTHOR]

Earthworms (EWs) could be a viable indicator of soil biology and agri-food system management. The influence of climate-smart agriculture (CSA)-based sustainable intensification practices (zero tillage, crop rotations, crop residue retention, and precision water and nutrients application) on earthworms' (EWs) populations and soil physico-biochemical properties of rice-wheat cropping system in the Indo-Gangetic plains of South Asia was investigated. This study investigates the effect of 10-years adoption of various CSA practices on the abundance of earthworms and physical and biochemical properties of the soil and EWs' casts (EWC). Five scenarios (Sc) were included: conventionally managed rice-wheat system (farmers' practices, Sc1), CSA-based rice-wheat-mungbean system with flood irrigation (FI) (Sc2) and subsurface drip irrigation (SDI) (Sc3), CSA-based maize-wheat-mungbean system with FI (Sc4), and SDI (Sc5). Results revealed that EWs were absent under Sc1, while the 10-year adoption of CSA-based scenarios (mean of Sc2–5) increased EWs' density and biomass to be 257.7 no. m−2 and 36.05 g m−2, respectively. CSA-based maize scenarios (Sc4 and Sc5) attained higher EWs' density and biomass over rice-based CSA scenarios (Sc2 and Sc4). Also, SDI-based scenarios (Sc3 and Sc5) recorded higher EWs' density and biomass over FI (Sc2 and Sc4). Maize-based CSA with SDI recorded the highest EWs' density and EWs' biomass. The higher total organic carbon in EWC (1.91%) than in the bulk soil of CSA-based scenarios (0.98%) and farmers' practices (0.65%) suggests the shift of crop residue to a stable SOC (in EWC). EWC contained significant amounts of C and available NPK under CSA practices, which were nil under Sc1. All CSA-based scenarios attained higher enzymes activities over Sc1. CSA-based scenarios, in particular, maize-based scenarios using SDI, improved EWs' proliferation, SOC, and nutrients storage (in soil and EWC) and showed a better choice for the IGP farmers with respect to C sequestration, soil quality, and nutrient availability. [ABSTRACT FROM AUTHOR]

Scrapie is a unique disease whose etiology is through protein infection rather than a biological agent. Genetic polymorphism at 136, 154 and 171 codons provide the susceptibility/ resistance to the disease outbreak. PCR-SSCP has been found to be a robust technique for the identification of genetic variants because of SNP in the ORF (open reading frame) of PrP gene efficiently at low cost, evidenced by novel DNA sequences resulted from the SSCP variants. Prevalence of susceptible alleles at 136, 154 and 171 codons however did not result into the scrapie disease clinical symptoms in indigenous sheep breeds. Polymorphism at other loci in indigenous sheep could have played significant role in prevention of disease symptoms in indigenous sheep. The traditional feeding and management exclusively on range grazing without any concentrate supplementation having any animal protein might be responsible for the protection of animals from scrapie disease infection despite presence of susceptible alleles in the indigenous sheep animals. [ABSTRACT FROM AUTHOR]

All the six strains of Volvariella volvacea were investigated for their lignocellulolytic potential. The strain VvS-4 and VvS-5 found to have maximum Carboxymethyl cellulase (CMCase) and Filter paperase (FPase) activity. The cellobiase activity was comparatively much higher than CMCase and FPase activity. Thus strain VvS-4 was found to be the best strain in terms of CMCase, FPase and cellobiase activity. The strain VvS-5 gave almost similar results except cellobiase activity. The xylanase activity was found maximum in strain VvS-4 i.e. 147 IU/100ml and lesser in VvS-5 (108 IU/ 100ml). Xylanase activity was higher than cellulase activity when it was correlated with enzyme activities. None of the cultures showed a detectable laccase activity. The maximum cellulose and hemicellulose degradation was found in VvS-4 and VvS-5 (21.86% and 21.48%; 44.80% and 46.13% respectively) compared to all other strains of V. volvacea and the minimum degradation in fresh paddy straw and control (uninoculated). The pattern of cellulose and hemicellulose degradation was similar in VvS-4 and VvS-5. [ABSTRACT FROM AUTHOR]

A new operon (designated the puc2BA operon) displaying a high degree of similarity to the original pucBA genes of Rhodobacter sphaeroides 2.4.1 (designated puc1) was identified and studied genetically and biochemically. The puc2B-encoded polypeptide is predicted to exhibit 94% identity with the original β-apoprotein. The puc2A-encoded polypeptide is predicted to be much larger (263 amino acids) than the 54-amino-acid puc1Aencoded polypeptide. In the first 48 amino acids of the puc2A-encoded polypeptide there is 58% amino acid sequence identity to the original puc1A-encoded polypeptide. We found that puc2BA is expressed, and DNA sequence data suggested that puc2BA is regulated by the PpsR/AppA repressor-antirepressor and FnrL. Employing genetic and biochemical approaches, we obtained evidence that the puc2B-encoded polypeptide is able to enter into LH2 complex formation, but neither the full-length puc2A-encoded polypeptide nor its N-terminal 48-amino-acid derivative is able to enter into LH2 complex formation. Thus, the sole source of α-polypeptides for the LH2 complex is puc1A. The role of the puc1C-encoded polypeptide was also determined. We found that the presence of this polypeptide is essential for normal levels of transcription and translation of the puc1 operon but not for transcription and translation of the puc2 operon. Thus, the puc1C gene product appears to have both transcriptional and posttranscriptional roles in LH2 formation. Finally, the absence of any LH2 complex when puc1B was deleted in frame was surprising since we know that in the presence of functional puc2BA, approximately 30% of the LH2 complexes normally observed contain a puc2B-encoded β-polypeptide. [ABSTRACT FROM AUTHOR]

Presents information pertaining to the biological role of the bacterium Rhodobacter spahaeroides 2.4.1. Capabilities of the bacterium; What do the mutant strains exhibit; How is it characterize.

The present study was undertaken at NSP Unit 6 Agricultural Research Farm and Main Experimental Station of Acharya Narendra Dev University of Agriculture and Technology, Uttar Pradesh, India, from July to November 2020, in which genetic variability and heritability of 250 recombinant inbred lines (F7) and their parents PUSA 44 and CSR 43 were evaluated and correlation studies were performed for grain yield and yield contributing traits. The experiment was conducted in two replications at two different and naturally occurring sodic conditions following a-lattice design. Analysis of variance revealed significant variations among the lines depicting inherent variability between lines. For attributes, viz., plant height, effective tillers plant-1, spikelet fertility percentage, test weight and grain yield plant-1, high phenotypic and genotypic coefficient of variation estimates were observed for both the locations indicating good scope for selection based on these traits. However, the attributes viz., test weight and effective tillers plant-1 values depicted the pertinent role of the environment and thus, require careful assessment in selection programs concerning these traits. For days to 50% flowering, filled grains panicle-1, spikelet fertility percentage, and grain yield plant-1, moderate heritability was discovered with a high genetic advance as a percentage of mean, indicating that there is less influence of environment over these traits. Correlation studies revealed a significant and positive association with these yield attributing traits. Mutual association between component traits exhibit variable responses at both locations, validating genotype and environment interactions among traits with respect to yield. [ABSTRACT FROM AUTHOR]

• Higher soil microbial biomass carbon (MBC) and nitrogen (MBN) was found under Climate Smart Agriculture (CSA) practices. • Extracellular enzyme activities were higher at tillering and panicle initiation stage of wheat plant growth • MBC, MBN and enzyme activity varied with wheat growth stages • Nutrient uptake,C mineralization and wheat grain yield were higher in CSA based scenarios. Climate smart agriculture (CSA) practices are emerging as sustainable alternative to conventional rice-wheat system to pull up natural resources degradation across south Asia. After five years of continuous CSA based experiment, a two years study was conducted to evaluate changes in microbial biomasses (microbial biomass carbon and nitrogen), enzyme activities (alkaline phosphatase, dehydrogenase and β -glucosidase), nutrient release and uptake (N, P and K) at different wheat crop growth stages. Effect of CSA practices was also studied for carbon mineralization in an incubation experiment. Four scenarios (Sc) were included in this study- conventional tillage (CT) based rice-wheat system (Sc1), partial CSA based rice-wheat-mungbean system (Sc2), full CSA based rice-wheat-mungbean system (Sc3), and full CSA based maize-wheat-mungbean system (Sc4). Soil samples were collected from scenarios at 0–15 and 15−30 cm depth at different growth stages of wheat crop namely sowing, crown root initiation (CRI), active tillering, panicle initiation, and harvesting. Analysis of soil was done for chemical properties viz. pH, electrical conductivity, available N, P, K, NPK uptake and mineralizable carbon and biological properties viz., microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), dehydrogenase activity (DHA), alkaline phosphatase activity (APA) and β-glucosidase. Significantly higher microbial biomass carbon (42 %) and nitrogen (79 %) were found in surface soil (0−15 cm depth) under CSA based scenarios (Sc2, Sc3 and Sc4) at harvest stage of wheat over CT based/ conventional scenario (Sc1). At surface soil, alkaline phosphatase, dehydrogenase and β -glucosidase activity was 58, 14 and 13 % higher in CSA based scenarios, respectively than CT based scenario. CSA based scenarios showed significantly higher C mineralization after 3 days of the incubation experiment at harvest. An increase of respectively 15, 48 and 17 % of N, P and K uptake was observed with CSA based scenarios than CT based scenario. At harvest stage, 7 % higher amount of dry matter was reported with full CSA based scenarios (mean of Sc2 to Sc4) compared to Sc1. Higher wheat grain yield of ∼10 % was recorded with CSA based scenarios over CT based scenario. Therefore, CSA based scenarios with improved biological properties and nutrient availability and uptake at different wheat growth stages resulted in higher yields and hence need to be popularized among the farmers. [ABSTRACT FROM AUTHOR]

In Indo-Gangetic plains (IGP) of India, natural resources (soil, water, and environment) are degrading under the conventional-till (CT)-based management practices in rice-wheat cropping system. A long-term field experiment was conducted to understand the soil bacterial diversity and abundance under different sets of management scenarios (Sc). The study comprised of four scenarios, namely, -Sc.I CT-based rice-wheat system (farmers’ practice); Sc.II, partial conservation agriculture (CA) based in which rice is under CT—wheat and mungbean under zero-tillage (ZT); Sc.III, full CA-based in which rice-wheat-mungbean are under ZT and Sc.IV, where maize-wheat-mungbean are under ZT. These scenarios varied in cropping system, tillage, and crop residue management practices. Using Illumina MiSeq sequencing technology, the variable regions V3-V4 of 16S rRNA were sequenced and the obtained reads were analyzed to study the diversity patterns in the scenarios. Results showed the presence of 53 bacterial phyla across scenarios. The predominant phyla in all scenarios were Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes which accounted for more than 70% of the identified phyla. However, the rice-based systems (Sc.I, Sc.II, and Sc.III) were dominated by phylum Proteobacteria; however, maize-based system (Sc.IV) was dominated by Acidobacteria. The class DA052 and Acidobacteriia of Acidobacteria and Bacteroidetes of Bacteroidia were exceptionally higher in Sc.IV. Shannon diversity index was 8.8% higher in Sc.I, 7.5% in Sc.II, and 2.7% in Sc.III compared to Sc.IV. The findings revealed that soil bacterial diversity and abundance are influenced by agricultural management practices as bacterial diversity under full CA-based management systems (Sc.III and Sc.IV) was lower when compared to farmer’s practice (Sc.I) and partial CA (Sc.II) scenarios. [ABSTRACT FROM AUTHOR]

A study was undertaken to study the correlation among yield contributing traits of coriander under two moisture regimns. The estimates of genotypic correlation coefficient were higher than their respective phenotypic correlation coefficients for most of the characters indicating strong genetic association between characters. The seed yield per plant showed positive and significant correlation with branches per plant, umbels per plant, seeds per umbel and test weight in normal environment, whereas with branches per plant and umbels per plant, under limited moisture environment. The highest direct and positive effect towards seed yield per plant was due to branches per plant followed by test weight, days to maturity, umbels per plants and seeds per umbel in a normal environment, whereas, in limited moisture environment, umbels per plant had the highest direct and positive effect followed by days to maturity, branches per plant, test weight and plant height. Thus branches per plant and umbels per plant had a high positive correlation as well as a high direct and positive effect towards seed yield per plant under both the environment and suggested that the aforesaid characters may be considered as important in breeding programmes aiming to coriander yield improvement. [ABSTRACT FROM AUTHOR]

The present investigation was undertaken to isolate, screen and evaluate a selected promising PGPR Brevibacillus brevis on cotton crop. Out of 156 bacterial isolates one of the most promising isolate was analyzed for the various PGP traits. A seed germination analysis was conducted with cotton seeds to evaluate the potential of the isolate to promote plant growth. The bacterial isolate was checked for its growth and survival at high temperatures. The isolate was also analyzed for the PGP traits exhibited after the heat treatment. To identify the isolate morphological, biochemical and molecular characterization was performed. The isolate was found positive for many of the PGP attributes like IAA, ARA, anti-fungal activity and ammonia production. Effect of seed bacterization on various plant growth parameters was used as an indicator. The isolate showed significant growth and exhibited various PGP traits at high temperature making it suitable as an inoculant for cotton crop. Isolate was identified as Brevibacillus brevis [SVC(II)14] based on phenotypic as well as genotypic attributes and after conducting this research we propose that the B. brevis which is reported for the first time for its PGP potential in cotton, exerts its beneficial effects on cotton crop through combined modes of actions. [ABSTRACT FROM AUTHOR]

The rice-wheat (RW) system, spanning 13.5 million hectares in South Asia, is crucial for food security and livelihoods. However, intensive conventional tillage-based practices have harmed soil and environmental health, decreased productivity trends and increased greenhouse gas emissions. This study aims to develop resilient, climate-smart cropping systems within the RW system, focusing on soil and crop productivity, economic viability, and reduced greenhouse gas (GHG) emissions. Over eight years, the study evaluated diverse parameters compared to farmer practices (FP) in seven scenarios (Sc), including one representing FP (Sc1) and six based on conservation agriculture (CA) principles. The study assessed system crop productivity, economic returns, soil quality (organic carbon; OC, nitrogen; N, phosphorus; P, potassium; K contents, bulk density; BD, soil aggregation, infiltration rates, microbial counts, and earthworm density), and GHG emissions. CA-based scenarios (Sc2 to Sc7) showed improved soil quality, lower bulk density, enhanced soil aggregation, and increased infiltration rates compared to Sc1. In the 0–15 cm layer, surface soil organic carbon (OC) and C stock were 63.7 % and 49.6 % higher, respectively, in CA-based scenarios. Additionally, available N, P and K contents in the surface layer increased by 10.2 %, 28.6 %, and 21.8 % under CA-based scenarios. Adoption of CA in intensified maize-based scenarios (Sc4 and Sc5) led to the increased system and economic yields, higher soil quality index (SQI), reduced GHG emissions and increased C stock compared to Sc1. The study highlights that Conservation Agriculture (CA) practices and diversified crop rotations can address issues like falling crop productivity, reduced economic returns, soil degradation, and increasing environmental impacts in northwestern India's traditional rice-wheat system. However, widespread adoption requires government policies, including C credit payments and guaranteed markets with supportive pricing. [Display omitted] • Crop diversification improves physical, chemical and biological properties. • Crop residue retention influences nutrient balances and biological properties. • Reduces greenhouse gas emissions and yield-scaled global warming potential. • Productivity and profitability increase through crop diversification and management. • Crop diversification and residue retention improve soil quality index. [ABSTRACT FROM AUTHOR]

Indo-Gangetic plains (IGP) of South Asia have supported bulk of human and bovine population in the region since ages, and a spectacular progress has been made in food production. However, malnutrition, diminishing total factor productivity, and natural resource degradation continue to plague this cereal-dominated region, which is also vulnerable to climate change. Addressing these challenges would require a transition towards diversifying cereal rotations with agroecological cropping systems. A study was, therefore, conducted at the experimental farm of ICAR-CSSRI, Karnal on crop diversification and sustainable intensification options using agro-ecological approaches such as Conservation Agriculture (CA) and diversified cropping systems to ensure food and nutritional security while sustaining the natural resources. On 2 years mean basis, CA-based cropping system management scenarios (mean of Sc2–Sc7) using diversified crop rotations; increased the system yield by 15.4%, net return by 28.7%, protein yield by 29.7%, while using 53.0% less irrigation water compared to conventional tillage (CT)-based rice–wheat system (Sc1). Maize-mustard-mungbean on permanent beds (PBs) (Sc4) recorded the highest productivity (+ 40.7%), profitability (+ 60.1%), and saved 81.8% irrigation water compared to Sc1 (11.8 Mg ha−1; 2190 USD ha−1; 2514 mm ha−1). Similarly, Sc5 (maize-wheat-mungbean on PBs) improved productivity (+ 32.2%), profitability (+ 57.4%) and saved irrigation water (75.5%) compared to Sc1. In terms of nutritional value, Sc5 was more balanced than other scenarios, and produced 43.8, 27.5 and 259.8% higher protein, carbohydrate and fat yields, respectively, compared to Sc1 (0.93, 8.55 and 0.14 Mg ha−1). Scenario 5 was able to meet the nutrient demand of 19, 23 and 32 additional persons ha−1 year−1 with respect to protein, carbohydrate and fat, respectively, compared to Sc1. The highest protein water productivity (~ 0.31 kg protein m−3 water) was recorded with CA-based soybean-wheat-mungbean (Sc6) system followed by maize-mustard-mungbean on PBs (Sc4) system (~ 0.29 kg protein m−3) and lowest under Sc1. Integration of short duration legume (mungbean) improved the system productivity by 17.2% and profitability by 32.1%, while triple gains in irrigation water productivity compared to CT-based systems. In western IGP, maize-wheat-mungbean on PBs was found most productive, profitable and nutritionally rich and efficient system compared to other systems. Therefore, diversification of water intensive cereal rotations with inclusion of legumes and CA-based management optimization can be potential option to ensure nutritious food for the dwelling communities and sustainability of natural resources in the region. [ABSTRACT FROM AUTHOR]

Plant-bacterial interactions in the rhizosphere are complex and determine the plant health, productivity and soil fertility. The Plant Growth Promoting bacterial strains were isolated from the rhizospheric soil of the cotton plant from various places of Haryana, India. One of the most promising isolate exhibiting maximum PGP traits was identified as Pseudomonas fluorescens based on the biochemical characterization, phenotypic microarray analysis and 16S rDNA sequencing. The isolate was initially screened on the basis of the seed germination assay and was then screened in vitro for their plant growth promoting traits like production of indoleacetic acid (IAA), ammonia production (NH3), hydrogen cyanide (HCN) production, siderophore production, phosphate solubilization, ACC deaminase activity and acetylene reduction activity (ARA). The isolate exhibited positive results for ammonia and siderophore production and phosphate solubilization. The isolate also showed acetylene reduction activity (ARA). The results indicated that P. fluorescens has significant potential when applied to soil-plant system to uncover its efficacy as effective PGPR. [ABSTRACT FROM AUTHOR]

Soil sodicity is a growing concern for crop growth and development in arid and semi-arid regions of the world. Conservation agriculture (CA) provides an effective solution towards reclamation of degraded sodic lands and enhance the crop productivity. A field experiment was carried out to assess the sodic soil reclamation potential of CA based management practices including zero tillage, legume (mungbean; Mb) rotation, residue (+R) mulch, and subsurface drip irrigation (SDI) for three years under rice-wheat (RW) system. The system scenarios (Sc) comprised of multiple indicators to measure their impact on soil properties as well as system productivity, profitability, water and nitrogen use efficiency. The results indicated that soil pH s under Sc5-Sc8 (CA-based SDI scenarios) was significantly (p < 0.05) lowered by 2.16, 2.16 and 1.33% compare with mean of Sc1 and Sc2 (CT-based system; 9.10, 8.29 and 8.14) at all three soil layers (0-5, 5-15 and 15-30 cm), respectively. Similarly, the exchangeable sodium percentage (ESP) was lowered by 2.9, 11.2 and 14.9% under CA-based scenarios with residue management compared with CT-based system (mean of Sc1 and Sc2; 15.2, 17.2 and 28.6%) during the study. The concentration of extractable anions (CO З 2‾, HCO З ‾, Cl‾) decreased notably whereas, soil organic carbon and soil solution cations (Na+, Ca2+, Mg2+) concentration were increased under CA based management SDI plots. In addition, CA with SDI scenarios (mean of Sc5-Sc8) proved to be more productive and water-efficient than CA-based flood irrigation (FI; mean of Sc3 and Sc4). Moreover, CA-based FI and SDI scenarios saved 29.5 and 60.7% irrigation water, and improved the partial factor productivity of nitrogen (PFP N) by 6.8 and 24.4%, respectively compared to CT-R (conventional tillage without residue) based Sc1. Therefore, CA practices can potentially reduce sodicity and improve soil chemical properties for profitable crop cultivation. [Display omitted] • Conservation agriculture (CA) practices demonstrated a significant reduction in soil sodicity. • CA in rice-wheat system significantly improved energy productivity (EP) and use efficiency (EUE). • CA with subsurface drip irrigation (SDI) system outperformed farmer's practices with 22% higher productivity, 41% higher profitability, and 46% irrigation water saving. • CA practices coupled with SDI hold great potential to reclaim sodic soil and achieve land degradation neutrality in India. [ABSTRACT FROM AUTHOR]

Improving soil water holding capacity (WHC) through conservation agriculture (CA)-practices, i.e., minimum mechanical soil disturbance, crop diversification, and soil mulch cover/crop residue retention, could buffer soil resilience against climate change. CA-practices could increase soil organic carbon (SOC) and alter pore size distribution (PSD); thus, they could improve soil WHC. This paper aims to review to what extent CA-practices can influence soil WHC and water-availability through SOC build-up and the change of the PSD. In general, the sequestered SOC due to the adoption of CA does not translate into a significant increase in soil WHC, because the increase in SOC is limited to the top 5–10 cm, which limits the capacity of SOC to increase the WHC of the whole soil profile. The effect of CA-practices on PSD had a slight effect on soil WHC, because long-term adoption of CA-practices increases macro- and bio-porosity at the expense of the water-holding pores. However, a positive effect of CA-practices on water-saving and availability has been widely reported. Researchers attributed this positive effect to the increase in water infiltration and reduction in evaporation from the soil surface (due to mulching crop residue). In conclusion, the benefits of CA in the SOC and soil WHC requires considering the whole soil profile, not only the top soil layer. The positive effect of CA on water-saving is attributed to increasing water infiltration and reducing evaporation from the soil surface. CA-practices' effects are more evident in arid and semi-arid regions; therefore, arable-lands in Sub-Sahara Africa, Australia, and South-Asia are expected to benefit more. This review enhances our understanding of the role of SOC and its quantitative effect in increasing water availability and soil resilience to climate change. [ABSTRACT FROM AUTHOR]

Climate-smart agriculture (CSA)-based management practices are getting popular across South-Asia as an alternative to the conventional system for particular weed suppression, resources conservation and environmental quality. An 8-year study (2012–2013 to 2019–2020) was conducted to understand the shift in weed density and diversity under different CSA-based management practices called scenarios (Sc). These Sc involved: Sc1, conventional tillage (CT)-based rice–wheat system with flood irrigation (farmers' practice); Sc2, CT-rice, zero tillage (ZT)-wheat–mungbean with flood irrigation (partial CA-based); Sc3, ZT rice–wheat–mungbean with flood irrigation (partial CSA-based rice); Sc4, ZT maize–wheat–mungbean with flood irrigation (partial CSA-based maize); Sc5, ZT rice–wheat–mungbean with subsurface drip irrigation (full CSA-based rice); and Sc6, ZT maize–wheat–mungbean with subsurface drip irrigation (full CSA-based maize). The most abundant weed species were P. minor > A. arvensis > M. indicus > C. album and were favored by farmers' practice. However, CSA-based management practices suppressed these species and favored S. nigrum and R. dentatus and the effect of CSAPs was more evident in the long-term. Maximum total weed density was observed for Sc1, while minimum value was recorded under full CSA-based maize systems, where seven weed-species vanished, and P. minor density declined to 0.33 instead of 25.93 plant m−2 after 8-years of continuous cultivation. Full CSA-based maize–wheat system could be a promising alternative for the conveniently managed rice–wheat system in weed suppression in north-west India. [ABSTRACT FROM AUTHOR]

In agriculture production system, soil enzymes are important indicators of soil quality. Measurements of soil quality parameter changes are essential for assessing the impact of soil and crop management practices. Keeping this in view, an experiment was conducted to evaluate the enzyme activities namely dehydrogenase (DHA), β-glucosidase, acid and alkaline phosphatase (AcP & AlP), fluorescein diacetate hydrolases (FDH), cellulase, urease and aryl sulphatase in rhizosphere and bulk soil after 8 years of different management regimes. Soil organic carbon (SOC), moisture content and few enzyme indices such as enzymatic pH indicator (AcP/AlP), alteration index three (Al3) and geometric mean (GMea) were also measured. The treatments were conventional rice-wheat system (termed as scenario (Sc1), CT system), partial conservation agriculture (CA)-based rice-wheat-mungbean system (Sc2, PCA-RW), partial climate smart agriculture (CSA)-based rice-wheat-mungbean system (Sc3), partial CSA-based maize-wheat-mungbean system (Sc4), full CSA-based rice-wheat-mungbean system (Sc5), and full CSA-based maize-wheat-mungbean system (Sc6). Soil samples were collected from rhizosphere and away from roots (bulk soil) at 0–15 cm soil depth before sowing (from rhizosphere of previous crops), at maximum tillering, flowering, and after harvesting of wheat crop. Results showed that DHA activity was higher before sowing (59.8%), at maximum tillering (48.4%), flowering (8.6%) and after harvesting (19.1%) in rice based CSA systems (mean of Sc3 and Sc5) over maize based CSA systems (mean of Sc4 and Sc6) in rhizospheric soil. On average, β-glucosidase activity was significantly higher in rhizospheric soils of rice based system over maize based CSA system. Before sowing of wheat, significantly higher (21.4%) acid phosphatase activity was observed in rhizosphere over bulk soils of maize based CSA system. Significantly higher alkaline phosphatase activity was observed before sowing of wheat in bulk soils of rice (25.3%) and maize (38.5%) based CSA systems over rhizospheric soils. Rice based CSA systems showed 27% higher FDH activity than maize based systems. Significant interaction effect was observed between the managements and enzymes. SOC played an important role in regulating the enzymes activity both in rhizosphere and bulk soil. Significant variation in AcP/AlP , Al3 and GMea was observed among the managements. Therefore, CSA managements are beneficial in improving enzyme activities not only in rhizosphere but also in bulk soil where residues are retained thereby may help in improving nutrient cycling. • Soil enzyme activities in rhizosphere and bulk soil were carried out with climate smart agriculture practices. • Residue retention and zero tillage improves enzyme activities in bulk soil. • Dehydrogenase and β-glucosidase activities were higher in rhizospheric soils of rice based system. • Urease activity was not affected by growth stages and climate smart agriculture practices. • SOC played an important role in regulating the enzymes activity in soil. [ABSTRACT FROM AUTHOR]

Intensive tillage coupled with crop residue burning in rice-wheat (RW) system is a serious issue that causes soil degradation and environmental pollution. Soil organic carbon (SOC) is one of the main indicators of soil health and system's sustainability. Zero-tillage has been widely recommended as an alternative for improving carbon sequestration in soil under different ecologies. But the SOC sequestration is very inconsistent and varied as it depends on the crop management practices. This study was performed in the western Indo-Gangetic plains (IGP) of India where RW system contributes 40% to the total country's food grain basket; however there exists issue of its sustainability because of declining SOC coupled with open field crop residue burning. Therefore, we evaluated the effects of different management scenarios (Sc) namely Sc1 (conventional till rice-wheat cropping system; business as usual), Sc2 (partial climate smart agriculture (CSA)-based rice-wheat-mungbean system), Sc3 (CSA-based rice-wheat-mungbean system), and Sc4 (CSA-based maize-wheat-mungbean system) on SOC pools and biological properties after 4 crop cycles (year 2009–2013). Soil samples were collected from surface and sub surface layers (0–15 and 15–30 cm soil depth) after rice harvesting in 2013. Results showed that the SOC stock at surface layer was higher by 70% with Sc4 than Sc1 (16.2 Mg C ha−1) (P < 0.05). All the forms of carbon in different pools were higher (P < 0.05) with Sc4 and Sc2 over Sc1 at 0–15 and 15–30 cm soil depths, respectively. At surface soil SOC pools were found in order of Sc4 > Sc3 > Sc2 > Sc1 (P < 0.05). Higher lability index (LI) (2.1) and stratification ratio (SR) (2.5) of organic carbon were observed in CSA-based systems (Sc2 and Sc4). At surface layer (0–15 cm) the CSA- based scenarios (mean of Sc2, Sc3 and Sc4) showed higher (P < 0.05) enzyme activities viz. dehydrogenase (641 μgTPF g−1 24 h−1) and alkaline phosphatase (158 μg p-nitrophenol g−1), and microbial biomass carbon (MBC) (787 μg g−1) and microbial biomass nitrogen (MBN)(98 μg g−1) compared with Sc1. Higher value of the basal soil respiration (34%) was also observed with CSA-based scenarios (Sc2, Sc3, Sc4). Surface soil layer showed maximum counts of fungi, bacteria and actinomycetes in Sc4. MBC, fungal population and SOC were the most sensitive biological soil parameters identified through principal component analysis (PCA) which can be used for soil quality assessment. Therefore, medium term adoption of climate smart agricultural practices involving zero-tillage, crop establishment, residue management and crop diversification in rice-wheat system can significantly improve the systems productivity by improving SOC and soil biological quality. • Organic carbon stock was improved under climate smart agriculture (CSA) based cereal systems. • MBC, MBN, microbial population and soil enzymes were improved in CSA. • CSA practices enhanced the systems productivity. • MBC, fungal population and SOC were the most sensitive indicators identified. [ABSTRACT FROM AUTHOR]

Continuous mono-cropping of rice-wheat (RW) system with conventional tillage (CT) based management practices have led to decline in soil health, groundwater table and farmers profit in north-west India. A medium-term (4 years) farmer's participatory strategic research trial of basmati RW system was conducted to evaluate the effects of conservation agriculture (CA) based management practices on crop yields, water productivity, profitability and soil quality. Six treatments were compared varied in the cropping system, tillage, crop establishment and residue management. CA-based management under zero-till direct seeded rice-wheat-mungbean recorded 36% higher system yield than conventional till rice-wheat system (14.91 Mg ha−1). CA-based rice-wheat system and rice-wheat-mungbean system saved ~35% irrigation water compared to conventional RW system (2168 mm ha−1). Total water productivity (WPI+R) was improved by 67% with CA-based rice-wheat-mungbean system (0.90 kg grain m−3) over the conventional system. On system basis, 42% higher net return was recorded with CA-based rice-wheat-mungbean system compared to conventional system (USD 2570 ha−1). Mungbean integration in basmati RW system contributed 29% share in system net returns across the treatments. Soil chemical and biological properties were improved by ~40% and 150%, respectively, with CA-based management system. [ABSTRACT FROM AUTHOR]

Carbon (C) mineralization of crop residues is an important process occurring in soil which is helpful in predicting CO2 emission to the atmosphere and nutrient availability to plants. A laboratory experiment was conducted in which C mineralization of residues of rice (Oryza sativa), wheat (Triticum aestivum), maize (Zea mays), mungbean (Vigna radiata) and their mixtures was applied to the soil surface or incorporated into an Alfisols from Northwest India. C mineralization was significantly affected by residue placement and type and their interactions. Rice residue had a higher decomposition rate (k = 0.121 and 0.076 day−1) than wheat (0.073 and 0.042 day−1) and maize residues (0.041 day−1) irrespective of placements. Higher decomposition rates of rice and wheat were observed when placed on soil surface than incorporated in the soils. Additive effects of the contribution of each residue type to C mineralization of the residue mixture were observed. When mungbean residue was added to the rice/wheat or maize/wheat mixture, decomposition of the residue mixture was enhanced. Crop residues with low N and high C/N ratio such as maize, wheat, rice and their mixtures can be applied on the soil surface for faster C and N mineralization, thereby helping to manage high volumes of residues under conservation agriculture-based practices in northwest India. [ABSTRACT FROM AUTHOR]

Soil quality degradation associated with resources scarcity is the major concern for the sustainability of conventional rice-wheat system in South Asia. Replacement of conventional management practices with conservation agriculture (CA) is required to improve soil quality. A field experiment was conducted to assess the effect of CA on soil physical (bulk density, penetration resistance, infiltration) and chemical (N, P, K, S, micronutrients) properties after 4 years in North-West India. There were four scenarios (Sc) namely conventional rice-wheat cropping system (Sc1); partial CA-based rice-wheat-mungbean system (RWMS) (Sc2); CA-based RWMS (Sc3); and CA-based maize-wheat-mungbean (Sc4) system. Sc2 (1.52 Mg m−3) showed significantly lower soil bulk density (BD). In Sc3 and Sc4, soil penetration resistance (SPR) was reduced and infiltration was improved compared to Sc1. Soil organic C was significantly higher in Sc4 than Sc1. Available N was 33% and 68% higher at 0-15 cm depth in Sc3 and Sc4, respectively, than Sc1. DTPA extractable Zn and Mn were significantly higher under Sc3 and Sc4 compared to Sc1. Omission study showed 30% saving in N and 50% in K in wheat after four years. Therefore, CA improved soil properties and nutrient availability and have potential to reduce external fertilizer inputs in long run. [ABSTRACT FROM AUTHOR]

Disposal of paddy residue has turn out to be a huge problem in north-west Indian states, resulting farmers prefer to burn the residues in-situ. Paddy residue management is of utmost important as it contains plant nutrients and improves the soil-plant-atmospheric continuum. Burning biomass not only pollutes environment and results in loss of appreciable amount of plant essential nutrients. The objectives of the review paper is to access the amount of residue generation, its utilization in-situ and ex-situ, emphasize harmful effects of residue burning on human health, soil health and environment of north-west states of India specially in Punjab and Haryana. This paper also discusses the possible strategies, financial and socio-economic evaluation of the paddy residue management technologies and accentuates the assessment of range of potential policy instruments which would offer avenues for sustainable agriculture and environment. Timely availability of conservation agriculture (CA) machinery is of utmost significance to manage the paddy residues in-situ. Collection and transportation of voluminous mass of paddy residue is cumbersome, therefore, ex-situ residue management is still not an economically viable option. The agricultural waste opens vivid options for its versatile usage and is possible if residue is collected and managed properly. It is a prerequisite for surplus residues to be used for CA. There is an urge to create awareness among farming communities to incline them to understand importance of crop residues in CA for sustainability and resilience of Indian agriculture. [ABSTRACT FROM AUTHOR]

Potassium fertilization is often neglected and /or ignored leading to imbalanced fertilization under intensive cultivation especially in the Indo Gangetic Plains (IGP) in North-West India. Recently conservation agriculture (CA) with crop residue retention has become quite popular among the farmers and land practitioners in India and globally. Crop residues are generally rich in potassium (K) content and its continuous addition under CA may impact K dynamics and supply to crops to some extent. Keeping this in view, a field experiment was conducted to assess the effect of long-term cereal-based CA on K supplying capacity in soil of North-West India. Both routine method (neutral normal ammonium acetate extractable) and quantity-intensity (Q/I) approach were adopted to predict K supply under CA vis-à-vis conventional agriculture. Available K and Q/I parameters were analyzed after 11 years of an experimental setup consisting of six scenarios i.e. Scenario 1 (Sc1): conventional till rice-wheat cropping system; Scenario 2 (Sc2): partial CA based rice-wheat-mungbean system; Scenario 3 (Sc3): full CA based rice-wheat-mungbean system; Scenario 4 (Sc4): full CA based maize-wheat-mungbean system; Scenario 5 (Sc5) and 6 (Sc6): same as Sc3 and Sc4 but with sub surface drip irrigation system. Results revealed that full CA based scenarios maintained significantly higher (p < 0.05) available K (145 mg kg−1) than Sc1 (86 mg kg−1). However, it was observed that Q/I approach helped in better understanding of K supply under long term CA soils than routine method. Regarding K availability, Sc6 was the best scenario with high values of planar K (0.147 cmol kg−1), labile K (0.325 cmol kg−1) and potential buffering capacity (PBCK) while Sc1 (without K fertilization or residue addition) presented lowest values of Q/I parameters. Partial CA (Sc2) maintained higher labile K (0.368 cmol kg−1) and equilibrium concentration ratio (CR e 0K) (1.93(mol L−1) 1/2 × 10−3) but very low PBCK (36.4 cmol kg−1 (mol L−1) −1/2) suggesting that K intensity shall not be sustained for long period of time and lead to soil K depletion over time. However, on an average, all full CA based scenarios maintained higher Q/I parameters over the conventional practice (Sc1), representing better ability to supply K both immediately and over a long period of time to meet crop requirement. The impact of maize-wheat-mungbean cropping system was prominently observed with respect to CR e 0Kover rice-wheat-mungbean system; whereas the effect of irrigation method was not significantly distinguishable. The study thus highlights the potential of long term crop residue retention under CA for improving and maintaining K supply to crops. [Display omitted] • Q/I approach was better than 1 N NH 4 OAC method for understanding K dynamics under long term CA. • Intensity and quantity parameters were higher in CA than conventional agriculture. • Partial CA maintained higher immediately available K but poor supplying capacity over long term. • Long term residue retention significantly impacts K dynamics under CA. [ABSTRACT FROM AUTHOR]

• Conservation agriculture enhances SOC, nutrient availability and enzyme activity. • Infiltration improved under conservation agriculture practices. • Soil pH, SOC stock, available zinc and iron were the key soil quality indicators. • Higher soil quality index in CA based treatments over conventional one. • Maize-wheat cropping system showed higher soil quality over rice–wheat system. Soil quality is of utmost essential for yield sustainability of intensive cereal based cropping system in North West Indo Gangetic plains of India. Hence, we evaluated long-term (10 years) effect of conservation agriculture (CA) practices on soil quality improvement under six different cropping scenarios (Sc), i.e. Sc1-represented by transplanted puddled rice (TPR) followed by conventional tilled broadcasted wheat (CT-wheat) with residue removal, Sc2-TPR rice followed by zero tillage (ZT) wheat and ZT-mung bean with partial residue retention, Sc3-direct seeded rice (DSR) followed by ZT-wheat and ZT-mung bean with full residue retention, Sc4-DSR is replaced by ZT-maize followed by ZT-wheat and ZT-mung bean, Sc5 and Sc6 were – Sc3 integrated with sub surface drip irrigation (SDI) and Sc4 + SDI, respectively. Soil samples were collected from 0 to 5, 5–15 and 15–30 cm soil depth from each scenario after harvesting of wheat in 2019. Results showed that, reduction in bulk density (BD), soil penetration resistance (SPR) and enhancement of water holding capacity and infiltration were associated with CA based scenarios (Sc3–Sc6). Scenario 3 recorded lowest BD of 1.39 and 1.58 g cm−3 at 0–5 and 5–15 cm soil depth, respectively. CA based Sc6 recorded highest infiltration rate (1.48 cm hr−1) and lowest was associated with Sc1 (0.5 cm hr−1). The enrichment of soil organic carbon (SOC) content, stock, available nitrogen and potassium was mainly confined to upper surface soil layer (0–5 cm). The SOC content and stock in CA based scenarios (average of Sc3 to Sc6) was 41–57 and 69–94% higher than Sc1 at 0–5 cm soil layer. Available nitrogen was increased by 23–50 and 64–98% and available potassium increased by 13–28 and 42–71% in 0–5 and 5–15 cm soil depth, respectively in CA based scenarios over Sc1. Similarly, microbial biomass carbon (MBC) and dehydrogenase (DHA) activity in top soil layer under CA based scenarios was increased by 177–195 and 67–107% over Sc1, respectively. The maximum SQI was registered with Sc6 (0.91) followed by Sc4 (0.89) and least was recorded in Sc1 (0.65) at 0–5 cm soil depth. Maize-wheat based cropping system recorded higher SQI over rice–wheat based cropping system. Sustainable yield index was strongly related with key soil quality indicators and also positively correlated with SQI. Thus our study suggests that CA based maize-wheat-mung bean cropping system should be recommended for better soil quality and yield sustainability in North West India. [ABSTRACT FROM AUTHOR]

This study was conducted over 3 years in a salt-affected coastal rainfed lowland ecosystem. Farmers most commonly grow tall rice varieties in the wet season to cope with flash and/or stagnant floods, leading to large amounts of rice residue production. Most of the land remains fallow during the dry season because of increased salinity and scarcity of freshwater for irrigation. The study aims to provide options for increasing cropping intensity through management of crop residues (CR) and soil salinity, conservation of soil moisture, and reduction in production cost. The rice–maize rotation was assessed with rice as the main plot as (1) puddled transplanted rice (PTR) with CR of both rice and maize removed, (2) PTR and 40% CR of both crops retained, (3) dry direct-seeded rice (DSR) with CR of both crops removed, and (4) DSR with 40% CR of both crops retained. Maize in the dry season was supplied with different N levels as sub-plots—control (0 kg N ha−1), 80, 120, and 160 kg N ha−1. DSR, when combined with CR retention (DSR + R), reduced soil salinity. The increase in rice grain yield with CR retention (observed in second and third years) and crop establishment (higher in DSR versus PTR in the third year) was 16 and 24%, respectively. The cost of production increased by 17% (USD 605 ha−1) in PTR compared with DSR (USD 518 ha−1). CR retention reduced irrigation water requirement by 37% and N requirement by 40 kg ha−1 for hybrid maize. When CR was removed (−R), the N requirement for hybrid maize increased to 160 kg N ha−1 compared to when it was partially (40%) retained, where the requirement was 120 kg ha−1 with similar yields. Available N was highest under DSR + R (314 kg ha−1) and lowest under PTR − R (169 kg ha−1), and it also increased with increasing N application up to 120 kg ha−1 (+R) and 160 kg ha−1 (−R). The results of the study hold promise for increasing cropping intensity and farmers' incomes, with broader implications for increasing productivity on about 2.95 million hectares currently under a rice–fallow system in eastern India, and in coastal areas affected by similar conditions in South and Southeast Asia. [ABSTRACT FROM AUTHOR]

In the western Indo-Gangetic plains, issues of deterioration in soil, water, and environment quality coupled with low profitability jeopardize the sustainability of the dominant rice–wheat (RW) system. To address these issues, crop diversification and conservation agriculture (CA)-based management hold considerable promise but the adoption of both approaches has been low, and additional evidence generation from a multi-criteria productivity and sustainability perspective is likely required to help drive the change. Compared to prevailing farmers' practice (FP), results suggest that CA-based rice management increased profitability by 13% and energy use efficiency (EUE) by 21% while reducing irrigation by 19% and global warming potential (GWP) by 28%. By substituting CA-based maize for rice, similar mean profitability gains were realized (16%) but transformative improvements in irrigation (− 84%), EUE (+ 231%), and GWP (− 95%) were observed compared to FP. Inclusion of mungbean in the rotation (i.e. maize-wheat-mungbean) with CA-based management increased the system productivity, profitability, and EUE by 11, 25 and 103%, respectively while decreasing irrigation water use by 64% and GWP by 106% compared to FP. Despite considerable benefits from the CA-based maize-wheat system, adoption of maize is not widespread due to uneven market demand and assured price guarantees for rice. [ABSTRACT FROM AUTHOR]