Effects of erect panicle genotype and environment interactions on rice yield and yield components

The dense and erect panicle (EP) genotype conferred by DEP1 has been widely used in the breeding of high-yield Chinese japonica rice varieties.However,the breeding value of the EP genotype has rarely been determined at the plant population level.Therefore,the effects of the interaction of EP genotype and the environment at different locations and times on rice yield and its various components were investigated in this study.Two sets of near-isogenic lines (NILs)of EP and non-EP (NEP) genotypes with Liaojing 5 (LG5) and Akitakomachi (AKI) backgrounds were grown in the field in 2016 and 2017 in Shenyang,China,and Kyoto,Japan.In 2018,these sets were grown only in Kyoto,Japan.The average yields of the EP and NEP genotypes were 6.67 and 6.13 t ha^(-1)for the AKI background,and 6.66 and 6.58 t ha^(-1)for the LG5 background,respectively.The EP genotype positively affected panicle number (PN) and grain number per square meter (GNPM),mostly resulting in a positive effect on harvest index (HI).In contrast,the EP genotype exerted a negative effect on thousand-grain weight (KGW).The ratio of the performance of the EP genotype relative to the NEP genotype in terms of yield and total biomass correlated positively with mean daily solar radiation during a 40-day period around heading.These results indicate that the effectiveness of the EP genotype depends on the availability of solar radiation,and the effect of this genotype is consistently positive for sink formation,conditional in terms of source capacity,and positive in a high-radiation environment.

Molecular characterization of sweet potato(Ipomoea batatas[L.]Lam)germplasms for desirable traits by using simple sequence repeats markers

Every breeding program that aims to create new and improved cultivars with desired traits mostly relies on information related to genetic diversity.Therefore,molecular characterization of germplasms is important to obtain target cultivars with desirable traits.Sweet potato[Ipomoea batatas(L.)Lam]is widely considered the world’s most important crop,with great diversity in morphological and phenotypic traits.The genetic diversity of 20 sweet potato germplasms originating from Bangladesh,CIP,Philippines,Taiwan,and Malaysia were compared,which was accomplished by genetic diversity analysis by exploring 20 microsatellite DNA markers for germplasm characterization and utilization.This information was effective in differentiating or clustering the sweet potato genotypes.A total of 64 alleles were generated using the 20 primers throughout the 20 germplasm samples,with locus IBS97 having the highest number of alleles(5),whereas locus IbU33 had the fewest alleles(2).The alleles varied in size from 105(IbU31)to 213 base pairs(IBS34).The Polymorphism Information Content(PIC)values for the loci IbL46 and IBS97 varied from 0.445 to 0.730.IBS97 has the highest number of effective alleles(3.704),compared to an average of 2.520.The average Shannon’s diversity index(H)was 1.003,ranging from 0.673 in IbU3 to 1.432 in IBS97.The value of gene flow(Nm)varied between 0.000 and 0.005,with an average of 0.003,whereas genetic differentiation(FST-values)ranged between 0.901 and 1.000.The sweet potato germplasm included in this study had a broad genetic base.SP1 vs.SP9 and SP12 vs.SP18 germplasm pairings had the greatest genetic distance(GD=0.965),while SP1 vs.SP2 germplasm couples had the least genetic diversity(GD=0.093).Twenty genotypes were classified into two groups in the UPGMA dendrogram,with 16 genotypes classified as group“A”and the remaining four genotypes,SP10,SP18,SP19,and SP20,classified as group“B.”According to cluster analysis,the anticipated heterozygosity(gene diversity)of Nei(1973)was 0.591 on average.In summary,SSR markers successfully evaluated the genetic relationships among the sweet potato accessions used and generated a high level of polymorphism.The results of the present study will be useful for the management of germplasm,improvement of the current breeding strategies,and the release of new cultivars as varieties.

Characterization of Endophytic Microorganisms of Rice(Oryza sativa L.)Potentials for Blast Disease Biocontrol and Plant Growth Promoting Agents

One hundred twenty-five endophytic microorganisms were isolated from the roots,stems,and leaves of four prominent rice cultivars growing in temperate regions.Their potential to combat rice blast disease and promote plant growth was investigated.The dual culture tests highlighted the strong antagonistic activity of five fungal(ranging from 89%–70%)and five bacterial(72%–61%)endophytes.Subsequent examination focused on volatile compounds produced by selected isolates to counter the blast pathogen.Among these,the highest chitinase(13.76μg mL−1)and siderophore(56.64%),was exhibited by Aspergillus flavus,and the highest HCN production was shown by Stenotrophomonas maltophilia(36.15μM mL−1).In terms of growth promotion traits,Aspergillus flavus and Enterobacter cloacae excelled in activities viz,phosphorous solubilization,ammonia production,auxin and gibberellic acid production,and nitrogen fixation.The Identity of these endophytes was confirmed through molecular analysis as Trichoderma afroharzianum,Trichoderma harzianum,Penicillium rubens,Aspergillus flavus,Stenotrophomonas rhizophila,Stenotrophomonas maltophilia,Bacillus cereus,Enterobacter cloacae,and Bacillus licheniformis.Under greenhouse conditions,the highest disease control was shown by isolate Bacillus licheniformis and A.flavus with an inhibition of 79%,followed by S.rhizophila(77%)and T.afroharzianum(73%).The overall results of this study showed that Bacillus licheniformis and Stenotrophomonas rhizophila have great potential to be used as bio-stimulant and biocontrol agents to manage rice blast disease.

Yield and Grain Quality Response of Spring Wheat Varieties to Irrigation and Fertility Management

Experiments were conducted in 2020 and 2021 in North Dakota to determine the effects of foliar and soil applied fertilizers, variety and irrigation on yield and grain quality of spring wheat. Foliar application of N did not consistently increase yield and protein indicating the soil N levels were adequate to optimize yield. The variety Bolles had higher protein content than Faller. Zinc (Zn) content in the grain was greatest when applied at either flowering or post anthesis. It was also found to be correlated with grain protein content. Yield and grain protein content were negatively related. There was no consistent effect of phosphorous or Zn when applied to the soil on yield, protein, gluten, or Zn content in the grain. Zinc concentration in the grain was significantly correlated with the protein, gluten and P content of the grain. The timing of Zn application was critical to the success of translocating Zn to the grain. Grain Zn concentration increased with most late season foliar Zn applications to both varieties indicating potential for enriching spring wheat nutrient content through production management practices already common in areas that grow spring wheat.

Artificial Intelligence for Maximizing Agricultural Input Use Efficiency: Exploring Nutrient, Water and Weed Management Strategies

Agriculture plays a crucial role in the economy,and there is an increasing global emphasis on automating agri-cultural processes.With the tremendous increase in population,the demand for food and employment has also increased significantly.Agricultural methods traditionally used to meet these requirements are no longer ade-quate,requiring solutions to issues such as excessive herbicide use and the use of chemical fertilizers.Integration of technologies such as the Internet of Things,wireless communication,machine learning,artificial intelligence(AI),and deep learning shows promise in addressing these challenges.However,there is a lack of comprehensive documentation on the application and potential of AI in improving agricultural input efficiency.To address this gap,a desk research approach was used by utilizing peer-reviewed electronic databases like PubMed,Scopus,Goo-gle Scholar,Web of Science,and Science Direct for relevant articles.Out of 327 initially identified articles,180 were deemed pertinent,focusing primarily on AI’s potential in enhancing yield through better management of nutrients,water,and weeds.Taking into account researchfindings worldwide,we found that AI technologies could assist farmers by providing recommendations on the optimal nutrients to enhance soil quality and deter-mine the best time for irrigation or herbicide application.The present status of AI-driven automation in agricul-ture holds significant promise for optimizing agricultural input utilization and reducing resource waste,particularly in the context of three pillars of crop management,i.e.,nutrient,irrigation,and weed management.

Variation in Grain Quality of Upland Rice from Luang Prabang Province, Lao PDR

Luang Prabang Province is located within the area recognized as the center of rice(Oryza sativa L.) diversity in Lao PDR. This study reported on grain quality characteristics of 60 upland rice seed samples sharing 49 variety names collected from 6 villages in Luang Prabang in 2015. Most of the samples has non-pigmented pericarp, while red pericarp was found in four samples and purple in five samples. Almost all of the samples were of large grain type, with glutinous endosperm in 70% and non-glutinous endosperm in 30%. The brown(unpolished) rice was found with a wide range of grain nutritional quality, including protein(9.2% ± 0.9%), Fe(15.9 ± 6.9 mg/kg), Zn(19.6 ± 2.1 mg/kg), anthocyanin(0.774 ± 0.880 mg/g), and anti-oxidative capacity(2.071 ± 1.373 mg/g). The varieties sharing similar names had similar morphological characteristics but varied in nutritional concentration, with required confirmation in genetic variation analysis. This study found that some rice varieties with high grain quality may benefit the farmers directly or could be used in varietal improvement programs.

Intensified cropping reduces soil erosion and improves rainfall partitioning and soil properties in the marginal land of the Indian Himalayas

Environmental crises,land degradation,declining factor productivity,and farm profitability questioned the sustainability of linear economy-based existing agricultural production model.Hence,there is a dire need to design and develop circular economy-based production systems to meet the twin objectives of environmental sustainability and food security.Therefore,the productive capacity,natural resource conserving ability,and biomass recycling potential of four intensified maize-based systems viz.maize(Zea mays)+sweet potato(Ipomoea batatas)-wheat,maize+colocasia(Colocasia esculenta)-wheat,maize+turmeric(Curcuma longa),and maize+ginger(Zingiber officinale)were tested consecutively for three years(2020,2021 and 22)in a fixed plot manner at Dehradun region of the Indian Himalaya against the existing maize-wheat systems.The result showed that the maize+sweet potato-wheat system significantly reduced runoff loss(166.3 mm)over the maize-wheat system.The highest through fall(68.12%)and the lowest stem flow(23.54%)were recorded with sole maize.On the contrary,the maize+sweet potato system has the highest stem flow(36.15%)and the lowest through fall.Similarly,the maize+sweet potato system had 5.6 times lesser soil erosion and 0.77 t ha^(-1)higher maize pro-ductivity over the maize-wheat system.Furthermore,the maize+sweet potato system recorded significantly higher soil moisture(19.3%),infiltration rate(0.95 cm h^(-1)),and organic carbon(0.78%)over the rest of the systems.The maize+sweet potato system also recycled the highest nitrogen(299.2 kg ha^(-1)),phosphorus,(31.0 kg ha^(-1)),and potassium(276.2 kg ha^(-1))into the soil system.Hence,it can be inferred that concurrent cultivation of sweet potato,with maize,is a soil-supportive,resource-conserving,and productive production model and can be recommended for achieving the circular economy targets in the Indian Himalayas.

Floral Homeostasis Breakdown in Endangered Plant <i>Valeriana jatamansi</i>Jones (Valerianaceae) in North Eastern Himalayan Region

An inhabitant of north western Himalayan region and a gynodioceious plant having a lot of medicinal properties, Valeriana jatamansi Jones (Valerianaceae) is an enlisted endangered plant in the world. It was introduced in the research station of North Bengal Agricultural University (27.06&degN 88.47&degE) situated in north eastern Himalayan region of Darjeeling district in the state of West Bengal from Sikkim Sangtok (27&deg25'N 88&deg31'E) of north Sikkim area in India for the purpose of conservation. As we noticed some irregular development of floral organs, we investigated some pertinent questions regarding ecological aberrations found in plants. We found plants introduced in north eastern Himalayan region changed their homology of number flower petals and position of stamens seen naturally in north western Himalayan region as per the reports. Was there any genetic or extreme environmental stress condition caused a sudden change in floral structure as it is generally known as a rare phenomenon and frequently not seen? What were the correlations of different floral parts and fitness of population in different morphotypes? We predicted possible outcomes of seed setting by univariate regression models in a particular environment in addition to this investigation. We proposed three models of heterozygousity for answering the reasons of unstable floral form from a general known floral form, where silent mutations help the plants to survive in adverse conditions in spite of deformed or variable formed of floral morphology.

Dry Weight Accumulation, Root Plasticity, and Stomatal Conductance in Rice (<i>Oryza sativa</i>L.) Varieties under Drought Stress and Re-Watering Conditions

Drought is one of the main factors limiting rice (Oryza sativa L.) productivity and has become an increasingly severe problem in many regions worldwide. Establishing breeding programs to develop new drought-tolerant varieties requires an understanding of the effect of drought on rice plants and the mechanisms of drought tolerance in rice. We conducted a pot experiment to explore growth characteristics, root plasticity, and stomatal conductance in six rice varieties (DA8, Malagkit Pirurutong, Thierno Bande, Pate Blanc MN1, Kinandang Patong, and Moroberekan) in response to different drought stress and re-watering conditions. Drought stress significantly depressed plant growth, root size, and stomatal conductance in all experimental varieties. These negative effects depended on both the variety and the severity of the drought stress treatment. Under moderate drought stress (10 days after drought treatment), growth was less influenced in roots than in shoots. In contrast, there was an opposite trend under severe drought stress (15 days after drought treatment), with growth being more severely affected in roots than in shoots. Rice plants recovered from drought stress in terms of dry matter accumulation, root size, and stomatal conductance after re-watering;however, the recovery pattern differed among varieties. DA8 exhibited the highest dry weight accumulation and root size (root length, root surface area, root volume, fine root length, and thick root length) under well-watered, drought stress, and re-watering conditions. Kinandang Patong showed the highest recovery ability in dry matter accumulation, root length, root surface area, and stomatal conductance after re-watering. Malagkit Pirurutong expressed the poorest recovery ability in dry matter accumulation after re-watering. These three varieties might be selected for further experiments focusing on the mechanisms of drought tolerance and recovery ability in rice.

Global wild rice germplasm resources conservation alliance:World Wild-Rice Wiring

Wild relatives of crop are key genetic resources serving as diversity reservoirs for crop improvement under changing environments.Rice(Oryza sativa)is one of the most important crops in the world,providing staple food for half of the world's population.Wild rice is thus a critical germplasm resource for sustained global food security,ensuring high production yields,improved quality,and stress resistance in the face of climate change.Wild rice is closely related to domesticated rice and has a rich genetic diversity and exceptional adaptability to extreme environments.It has played a pivotal role in the history of rice hybridization and has become a key resource for rice breeding programs.The identification of wild-type cytoplasmic male sterility resources paved the way for the achievement of the“three lines”goal in hybrid rice,leading to a significant increase in rice yields.In addition,the use of resistance alleles found in wild rice is making rice production more resilient to losses caused by environmental stresses.However,wild rice germplasm resources are threatened due to habitat destruction and other anthropogenic factors.At the same time,the lack of centralized distribution of wild rice has hampered the sharing of basic information on wild rice resources and the utilization and conservation of wild rice in each country,as well as collaboration among scientists.

Effects of Green Manures and Zinc Fertilizer Sources on DTPA-Extractable Zinc in Soil and Zinc Content in Basmati Rice Plants at Different Growth Stages

Rice is very sensitive to low zinc(Zn) supply in submerged paddy soils and Zn deficiency is one of the major limiting factors in determining rice production in India. A field experiment was conducted during the summer-rainy seasons of 2009 and 2010 at the research farm of the Indian Agricultural Research Institute, New Delhi, to determine the effects of summer green manure crops and Zn fertilizers on diethylenetriaminepentaacetic acid(DTPA)-extractable(available) Zn concentration in soil and total Zn content in Basmati rice cultivar Pusa Basmati 1 at periodic intervals. Summer green manure crops included Sesbania aculeata(Dhaincha),Crotalaria juncea(Sunhemp), and Vigna unguiculata(Cowpea) and the Zn fertilizers used were ethylenediaminetetraacetic acid(EDTA)-chelated Zn, ZnSO4·7H2O, ZnSO4·H2O, ZnO, and ZnSO4·7H2O + ZnO. Beneficial effects of summer green manure crops and Zn fertilizers on DTPA-extractable Zn concentration in soil and total Zn content in dry matter of Basmati rice at periodic intervals were observed, with significant increases in all the determined parameters, in comparison with those in the control(no Zn application or summer fallow). The rate of increase varied among summer green manure crops and Zn fertilizers during both years. Among the summer green manures, incorporation of S. aculeata led to a significant increase in mean Zn content in Basmati rice grain and straw when compared with C. juncea, V. unguiculata, and summer fallow treatments. Among the Zn fertilizers, significant increases in Zn content in Basmati rice dry matter and DTPA-extractable Zn concentration in soil during various growth stages of the plant were recorded with EDTA-chelated Zn application, followed by the application of ZnSO4·7H2O, ZnSO4·H2O, ZnSO4·7H2O + ZnO, ZnO,and no Zn. The highest mean Zn content in Basmati rice grain and straw was recorded with EDTA-chelated Zn application in 2009 and 2010, respectively. The application of ZnSO4·7H2O was the second best treatment after EDTA-chelated Zn;however, it was statistically inferior to EDTA-chelated Zn. The lowest values were recorded with the control(no Zn application) during both years of study. The amount of Zn concentration in soil was found to be significantly positively correlated with the Zn content in Basmati rice dry matter during both years. Significantly higher levels of residual fertility in soil after the harvest of Basmati rice were observed with application of EDTA-chelated Zn and incorporation of S. aculeata when compared with those of other Zn sources and summer green manures.

Loss-of-Function of a Ubiquitin-Related Modifier Promotes the Mobilization of the Active MITE mPing

Miniature inverted-repeat transposable elements （MITEs） are widespread in both prokaryotic and eukaryotic genomes, where their copy numbers can attain several thousands. Little is known, however, about the genetic factor（s） affecting their transpositions. Here, we show that disruption of a gene encoding ubiquitin-like protein markedly enhances the transposition activity of a MITE roPing in intact rice plants without any exogenous stresses. We found that the transposition activity of roPing is far higher in the lines harboring a non-functional allele at the Rurml （Rice ubiquitin-related modifier-I） locus than in the wild-type line. Although the alteration of cytosine methylation pattern triggers the activation of transposable elements under exogenous stress conditions, the methylation degrees in the whole genome, the roPing-body region, and the roPing-flanking regions of the non-functional Rurml line were unchanged. This study provides experimental evidence for one of the models of genome shock theory that genetic accidents within cells enhance the transposition activities of transposable elements.

Crop productivity,soil health,and energy dynamics of Indian Himalayan intensified organic maize-based systems

The sustainability of prevailing maize-fallow system in rainfed ecosystems of the Eastern Himalayan region(EHR)of India is often questioned due to poor economic return and negative impact on soil health.Hence,the six cropping systems,maize-fallow(M-F),maize t cowpea-rapeseed(M t C-Rs),maize t cowpea-buckwheat(M t C-Bw),maize t cowpea-barley(M t CeB),maize t cowpea-garden pea(M t C-GP)and maize t cowpeaerajmash(M t C-R)in the main plot and three soil moisture conservation measures,no-mulch(NM),maize stover mulch(MSM)and maize stover t weed biomass mulch(MSM t WBM)in sub-plot were evaluated for four consecutive years(2014-18)at a Research Farm in fixed plot fashion.Results indicated that cowpea co-culture with maize and inclusion of winter crop increased maize yield by 6.2e23.5%over M-F.Among the systems,the M t C-GP recorded the highest crop productivity.The residual effect of MSM t WBM increased maize grain yield by 19.1%over NM.Cultivation of maize t cowpea-winter crops significantly improved the available N(3.2e12.9%),P(3.6 e12.7%),K(1.9e26.3%),organic carbon(9.2e16.8%),microbial biomass carbon-MBC(15.2e43.9%)and dehydrogenases-DHA(17.2e42.3%)in soil at 0e15 cm depth as compared to M-F.The M t C-GP also recorded maximum net return(US$2460 ha1),benefit:cost(B:C)ratio(2.86)and energy use efficiency(7.9%).The MSM t WBM recorded higher net return(US$1680 ha1)and B:C ratio(2.46)over NM.Hence,cowpea t maize-garden pea(M t C-GP)along with the application of MSM t WBM is a sustainable production practice to intensify the organically managed maize-fallow system in rainfed regions of the EHR of India and other similar ecosystems.

Multi-scale processes influencing global carbon storage and land-carbon-climate nexus:A critical review

Carbon(C)is a key constitutive element in living organisms(plants,microbes,animals,and humans).Carbon is also a basic component of agriculture because it plays a dynamic role in crop growth,development,nutrient cycling,soil fertility,and other agricultural features.The presence of C enhances soil physical,chemical,and biological properties.The C cycle supports all life on the Earth by transferring C between living organisms and the environment.The global climate is changing,and this change is attributable to the release of carbon dioxide and other greenhouse gases from human activities.Owing to the global climate change,agriculture is expected to be majorly affected.Agricultural production is directly linked to the climate.The five main global C pools are the oceanic,geologic,pedologic,atmospheric,and biotic pools,with specific reservoirs and inter-pool fluxes.The soil organic matter has various organic C pools(active,slow,and passive pools),containing various C-based fractions and specific liability pools.Climate,geology,land use,and management techniques are some of the variables that affect organic C and its reservoirs.The dynamics of each of these variables must be understood for a thorough knowledge of how they impact the soil C pools and storage capacity under the changing climate conditions.This review provides a comprehensive overview of the various factors that affect soil C pools/fractions and their C sequestration capacity.

Soil Microbiological Activity and Carbon Dynamics in the Current Climate Change Scenarios:A Review

Microbial activities are affected by a myriad of factors with end points involved in nutrient cycling and carbon sequestration issues.Because of their prominent role in the global carbon balance and their possible role in carbon sequestration, soil microbes are very important organisms in relation to global climate changes. This review focuses mainly on the responses of soil microbes to climate changes and subsequent effects on soil carbon dynamics. An overview table regarding extracellular enzyme activities(EAA) with all relevant literature data summarizes the effects of different ecosystems under various experimental treatments on EAA. Increasing temperature, altered soil moisture regimes, and elevated carbon dioxide significantly affect directly or indirectly soil microbial activities.High temperature regimes can increase the microbial activities which can provide positive feedback to climate change, whereas lower moisture condition in pedosystem can negate the increase, although the interactive effects still remain unanswered. Shifts in soil microbial community in response to climate change have been determined by gene probing, phospholipid fatty acid analysis(PLFA),terminal restriction length polymorphism(TRFLP), and denaturing gradient gel electrophoresis(DGGE), but in a recent investigations,omic technological interventions have enabled determination of the shift in soil microbe community at a taxa level, which can provide very important inputs for modeling C sequestration process. The intricacy and diversity of the soil microbial population and how it responds to climate change are big challenges, but new molecular and stable isotope probing tools are being developed for linking fluctuations in microbial diversity to ecosystem function.

Chrysanthemum Growth Gains from Beneficial Microbial Interactions and Fertility Improvements in Soil Under Protected Cultivation

An investigation was undertaken to analyse the influence of microbial inoculants on growth and enzyme activities elicited, and soil microbiome of two varieties of Chrysanthemum morifolium Ramat, which were grown under protected mode of cultivation. Rhizosphere soil sampling at 45 and 90 DAT(days after transplanting of cuttings) revealed up to four- to five-fold enhancement in the activity of defence-, and pathogenesisrelated, and antioxidant enzymes, relative to the uninoculated control. Plant growth and soil microbial parameters, especially soil microbial biomass carbon and potential nitrification exhibited significant increases over control. Available soil nitrogen concentrations showed 40%–44% increment in inoculated treatments. Scanning electron microscopy of the root tissues revealed biofilm-like aggregates and individual short bits of cyanobacterial filaments. Analyses of DGGE profiles of archaeal and bacterial communities did not show temporal variations(between 45 and 90 DAT). However,distinct influences on the number and abundance of phylotypes due to microbial inoculants were recorded. The inoculants — Cyanobacterial consortium(BF1- 4) and Anabaena sp.–Trichoderma sp. biofilm(An-Tr) were particularly promising in terms of the plant and soil related parameters,and remained distinct in the DGGE profiles generated. The effect of Trichoderma viride–Azotobacter biofilm on soil bacterial and archaeal communities was unique and distinct as a separate cluster. This study highlights that microbial inoculants exert positive effects, which are specific even to the rhizosphere soil microbiome of chrysanthemum varieties tested. Such inoculants can serve as soil fertility enhancing options in protected floriculture.

Conservation agriculture in India-Problems,prospects and policy issues

Conservation agriculture(CA)technologies involve minimum soil disturbance,permanent soil cover through crop residues or cover crops,and crop rotations for achieving higher productivity.In India,efforts to develop,refine and disseminate conservation-based agricultural technologies have been underway for nearly two decades and made significant progress since then even though there are several constraints that affect adoption of CA.Particularly,tremendous efforts have been made on no-till in wheat under a rice-wheat rotation in the Indo-Gangetic plains.There are more payoffs than tradeoffs for adoption of CA but the equilibrium among the two was understood by both adopters and promoters.The technologies of CA provide opportunities to reduce the cost of production,save water and nutrients,increase yields,increase crop diversification,improve efficient use of resources,and benefit the environment.However,there are still constraints for promotion of CA technologies,such as lack of appropriate seeders especially for small and medium scale farmers,competition of crop residues between CA use and livestock feeding,burning of crop residues,availability of skilled and scientific manpower and overcoming the bias or mindset about tillage.The need to develop the policy frame and strategies is urgent to promote CA in the region.This article reviews the emerging concerns due to continuous adoption of conventional agriculture systems,and analyses the constraints,prospects,policy issues and research needs for conservation agriculture in India.

Tillage and residue management effect on soil properties,crop performance and energy relations in greengram(Vigna radiata L.)under maize-based cropping systems

Effect of tillage and crop residue management on soil properties,crop performance,energy relations and economics in greengram(Vigna radiata L.)was evaluated under four maize-based cropping systems in an Inceptisol of Delhi,India.Soil bulk density,hydraulic conductivity and aggregation at 0-15 cm layer were significantly affected both by tillage and cropping systems,while zero tillage significantly increased the soil organic carbon content.Yields of greengram were significantly higher in maize-chickpea and maize-mustard systems,more so with residue addition.When no residue was added,conventional tillage required 20%higher energy inputs than the zero tillage,while the residue addition increased the energy output in both tillage practices.Maize-wheat-greengram cropping system involved the maximum energy requirement and the cost of production.However,the largest net return was obtained from the maize-chickpea-greengram system under the conventional tillage with residue incorporation.Although zero tillage resulted in better aggregation,C content and N availability in soil,and reduced the energy inputs,cultivation of summer greengram appeared to be profitable under conventional tillage system with residue incorporation.