Relay Cropping Research Articles

Strengthening the Resilience of Rain Fed Maize, Millet and Sorghum based Multiple Cropping Systems in the District of Bla in the Semi-Arid Area of Mali

One experiment was conducted in the district of Bla during the rainy seasons 2015 and 2016. The object was to test in farmer field’s technique package susceptible to improve crop yields and income in the context of climate change. The relay cropping of maize-cowpea, the intercropping of millet-cowpea and sorghum-cowpea with and without technique package were assessed in a dispersed blocks experimental design where each farmer was representing one replication. The technique package was involving: confection of diguettes perpendicular to the direction of the slope, use of improved and soaked seed, mineral fertilizer micro dosing and seeding mechanization, plant density, sowing at right date. The practice of technique package has significantly improved crop yields (53% for maize and 75% for cowpea in relay cropping; 73% and 60% for millet and cowpea in intercropping; 49% and 39% for sorghum and cowpea in intercropping). It has allowed improvement in the water use efficiency (62% in the relay cropping, 70% in the intercropping millet-cowpea and 47% in the intercropping sorghum-cowpea). Net benefits of 125 000, 112 000 and 121 000 FCFA/ha were from the relay cropping, intercropping millet and sorghum-cowpea. The anticipation of the practice of recommended agricultural techniques has improved the resilience of the cropping systems. Yield of the cropping systems and farmer’s income have been improved in the context of climate change.

Transforming Triple Cropping System to Four Crops Pattern: An Approach of Enhancing System Productivity through Intensifying Land Use System in Bangladesh

Changing three crops pattern to four crops can play a potential role for achieving countries food security. With this view to increase crop productivity, production efficiency, land use efficiency, and economic return through intensifying cropping intensity as well as crop diversity by transforming three crops pattern to four crops, the experiment was conducted in High Ganges River Floodplain Soils under the Agro-Ecological Zone (AEZ) 11 at Pali, Durgapur, under the Multilocation Testing Site, Puthia, Rajshahi, for two consecutive years 2014-15 and 2015-16. Four crops pattern mustard-onion/maize-T. Aman rice was tested at on-farm condition over the existing three crops pattern mustard-onion-T. Aman rice. Maize was introduced here as a relay crop with onion to fit it in the four crops pattern. The experiment was laid out in RCB design with six dispersed replications. Two-year crop cycles were completed, and data regarding component crops yield were considered for assessing the performance of the two cropping patterns for making a sense of comparing productivity. Although there was no significant difference in component crops yield between four crops and three crops pattern, as an additional crop, maize tremendously increased the system productivity and economic return of the four crops pattern. Higher rice equivalent yield 28.96 t·ha−1 in 2013-14 and 30.95 t·ha−1 in 2014-15 was recorded from the four crops pattern with a mean rice equivalent yield (REY) 29.95 t·ha−1 over the existing pattern with a mean value 21.76 t·ha−1. However, four crops pattern resulted in higher cultivation cost due to growing maize as an additional crop; nevertheless, it gave the higher gross return, marginal return, marginal benefit cost ratio, and production efficiency. The four crops pattern resulted averagely 37.63% higher production (REY) compared to the existing three crops pattern. Production as well as land use efficiency were increased by 9.33% and 19.18%, respectively, from the intensified alternate pattern.

Small Farmers and Resource-Conserving Agriculture: The Prospect of Attaining Environmental Sustainability through Zero Tillage Relay Cropping in Bangladesh

Small Farmers and Resource-Conserving Agriculture: The Prospect of Attaining Environmental Sustainability through Zero Tillage Relay Cropping in Bangladesh

Irrigation scheduling inMentha arvensis L. based relay and sequential cropping with Triticum aestivum L.

The soil of the experimental site was sandy loam in texture, neutral in reaction, rich in organic carbon, low in available nitrogen and high in available phosphorus and potassium. The bulk density of the top 0-15 cm soil was 1.46mg/m 3 . The basic infiltration rate was 1.3cm/hour. Twelve treatments comprising of three cropping systems (timely planted menthol mint, wheat + menthol mint relay system and wheat–late transplanted mint sequential cropping) and four irrigation schedules (IW:CPE ratio 0.6, 0.8, 1.0 and 1.2) were set in a Factorial Randomized Block Design with three replications. Different treatments failed to bring significant variations in number of tillers/m 2 at 65DAS. However, higher number of tillers/m 2 was scored by conventional wheat planting. The yield attributes of wheat (number of ears/m 2 , ear length, number of grains/ear, grain weight/ear and 1000 grain weight) expressed non-significant variations due to alteration in planting pattern. Timely planted sole mint exhibited the lowest mint oil equivalent yield, followed by the transplanted crop. The relayed crop yielded the maximum mint oil equivalent yield. Among different IW:CPE ratios, significant increase in mint oil equivalent yield was observed at higher moisture regimes. IW:CPE ratio 1.2 had the maximum and 0.6 the minimum mint oil equivalent yield. The interaction effect revealed that irrigation of relay cropped mint at IW:CPE ratio 1.2 produced the highest oil equivalent yield. The wheat + mint relay cropping system gave the maximum gross (Rs. 140079/ha) and net returns (Rs. 74509/ha) and B:C ratio (1.13). Timely sown sole mint fetched higher gross and net returns and B:C ratio than wheat–transplanted mint with non-significant differences. Irrigation at higher IW:CPE ratios resulted in significant increase in gross return for every successive irrigation levels. For net return and B:C ratio, IW:CPE ratio 1.2 proved to be the best although it was statistically at par with 1.0 IW:CPE ratio.

Influence of rice (Oryza sativa) habit groups and moisture conservation practices on soil physical and microbial properties in rice + lathyrus relay cropping system under rice fallows in Eastern Plateau of India

The study involving bio-physical aspects of popular rice (Oryza sativa L.) + lathyrus relay system for conserving natural resources and deriving the best benefits out of them was carried out in a vertisols at Indira Gandhi Krishi Vishwa Vidyalaya, Raipur (India) during 2011-14. The study location comes under tropical sub humid climate that receives an annual precipitation of 1582 mm. Two rice habit groups (a tall local rice Masuri maturing at 140 days visà -vis a dwarf HYV of rice Swarna with 110 days duration) were combined with two moisture conservation practices (retaining rice stubble height up to 15 cm versus 30 cm) for growing two contrasting varieties of lathyrus (early high biomass accumulating Ratan vis-à -vis medium high biomass Prateek). The study showed that soil moisture depletion pattern was relatively lower in case of residue retention at a higher cutting height, i.e. 30 cm in comparison to 15 cm with better and higher crop cover in the former. At later stages of lathyrus, faster moisture depletion was observed in case of lathyrus Ratan over that in Prateek. Yet, maximum soil moisture depletion was recorded under Prateekespecially under long rice habit group since it stayed for long as compared to ‘Ratan’. Similarly, bulk density (BD) was increased slightly with both time and soil compaction as a result of tillage or soil traffic. Soil strength indicated higher order variation (0.13 to 0.19) which could explain relatively higher sensitivity of soil strength to relay cropping situation in comparison to BD. However, marginal changes did occur in respect of soil porosity (47- 50%), pH (6.6 to 7.2) and EC (0.12 to 0.14 dS/m) at 15 cm profile depth. Moreover, as a result of slow depletion of soil moisture storage (SMS) following stubble retained at 30 cm height, soil organic carbon (SOC) status was greatly enhanced under it. Similar small increments in respect of soil fertility attributes such as soil available N (193.4 to 210.4 kg/ha), soil-P (10.3 to 12.2 kg/ha), soil-K (465.4 to 475.4 kg/ha), Cu (2.2 to 2.5 mg/kg), Fe (6.9-7.6 mg/kg), Zn (0.69-0.84 mg/kg) and Mn (6.2-6.9 mg/kg) after the harvest of rice were observed with diverse treatment combinations. Similarly, soil microbiological properties such as Rhizobium, dehydrogenase activity, crop growth and nodulationdid affect following treatment imposition. Besides these, weed dynamics and the resultant yield attributes and grain yield were favoured especially in those treatments where soil moisture is conserved (higher SMS) and availability of it was extended over a period of time. Therefore, the study carried out in a lentil relayed with diverse rice habits showed that efficient management of soil and land resources was crucial for realizing higher output through adequate soil cover with better soil health.

Agronomic management of lentil under relay cropping system

A field experiment was conducted at District Seed Farm, Kalyani, Bidhan Chandra Krishi Viswavidyalaya (22.97oN, 88.43oE, 9.75m MSL), Nadia, West Bengal, India during rabi season of 2014-16 to identify the optimum seed rate and variety for relay cropping with transplanted long duration kharif rice under changing onset of monsoon. The experiment was laid down in split plot design with three replications comprising of three lentil varieties (PL6, WBL 77 and NDL 1) in main plot and four seed rates (50, 60, 70 and 80 kg ha-1) in sub-plot. The varieties and seed rates significantly affected the plant population, pods per plant, biological and seed yield. The lentil variety PL 6 recorded highest seed yield (1446.8 kg ha-1) with the seed rate of 60 kg ha-1 followed by WBL 77 and NDL 1. Among the varieties PL6 recorded highest test weight (27.58 g) followed by NDL 1 (18.36 g) and WBL 77 (16.20 g). The variety PL 6 exhibited highest seed yield which was mainly attributed by the highest test weight of seeds along with moderate plant population m-2 and number of pods plant-1.

Agronomic management of lentil under relay cropping system

A field experiment was conducted at District Seed Farm, Kalyani, Bidhan Chandra Krishi Viswavidyalaya (22.97oN, 88.43oE, 9.75m MSL), Nadia, West Bengal, India during rabi season of 2014-16 to identify the optimum seed rate and variety for relay cropping with transplanted long duration kharif rice under changing onset of monsoon. The experiment was laid down in split plot design with three replications comprising of three lentil varieties (PL6, WBL 77 and NDL 1) in main plot and four seed rates (50, 60, 70 and 80 kg ha-1) in sub-plot. The varieties and seed rates significantly affected the plant population, pods per plant, biological and seed yield. The lentil variety PL 6 recorded highest seed yield (1446.8 kg ha-1) with the seed rate of 60 kg ha-1 followed by WBL 77 and NDL 1. Among the varieties PL6 recorded highest test weight (27.58 g) followed by NDL 1 (18.36 g) and WBL 77 (16.20 g). The variety PL 6 exhibited highest seed yield which was mainly attributed by the highest test weight of seeds along with moderate plant population m-2 and number of pods plant-1.

Relay cropping of wheat (Triticum aestivum L.) in cotton (Gossypium hirsutum L.) improves the profitability of cotton-wheat cropping system in Punjab, Pakistan.

Delayed sowing of wheat (Triticum aestivum L.) in cotton-based system reduces the productivity and profitability of the cotton-wheat cropping system. In this scenario, relay cropping of wheat in standing cotton might be a viable option to ensure the timely wheat sowing with simultaneous improvement in wheat yields and system profitability. This 2-year study (2012-2013 and 2013-2014) aimed to evaluate the influence of sowing dates and relay cropping combined with different management techniques of cotton sticks on the wheat yield, soil physical properties, and the profitability of the cotton-wheat system. The experiment consisted of five treatments viz. (S1) sowing of wheat at the 7th of November by conventional tillage (two disc harrows + one rotavator + two plankings) after the removal of cotton sticks, (S2) sowing of wheat at the 7th of November by conventional tillage (two disc harrows + two plankings) after the incorporation of cotton sticks in the field with a rotavator, (S3) sowing of wheat at the 7th of November as relay crop in standing cotton with broadcast method, (S4) sowing of wheat at the 15th of December by conventional tillage (two disc harrows + one rotavator + two plankings) after the removal of cotton sticks, and (S5) sowing of wheat at the 15th of December by conventional tillage (two disc harrows + two plankings) after the incorporation of cotton sticks in the field with a rotavator. The highest seed cotton yield was observed in the S5 treatment which was statistically similar with the S3 and S4 treatments; seed cotton yield in the S1 and S2 treatments has been the lowest in both years of experimentation. However, the S2 treatment produced substantially higher root length, biological yield, and grain yield of wheat than the other treatments. The lower soil bulk density at 0-10-cm depth was recorded in the S2 treatment which was statistically similar with the S5 treatment during both years of experimentation. The volumetric water contents, net benefit, and benefit-cost ratio were the highest in the S3 treatment during both years of experimentation. Thus, relay cropping of wheat in standing cotton might be a viable option to improve the soil physical environment and profitability of the cotton-wheat cropping system.

Soaking seeds with paclobutrazol enhances winter survival and yield of rapeseed in a rice-rapeseed relay cropping system

Rice-rapeseed relay cropping is an effective way to use winter fallow fields and increaseland use efficiency. However, the overlapping period of 10–15 days for rice-rapeseedcultivation results in reduced winter survival and less yields. Therefore, in this study, weinvestigated if the treatment of oil rape seeds with paclobutrazol (PAC) improves its winterhardiness and yields by altering its crop morphology. First, a pot experiment was conducted todetermine the appropriate PAC concentration to soak seeds upon seedling growth and thegermination rate. Another pot trial was performed to check the responses of different rapeseedcultivars to the proposed treatment. Rapeseed was cultivated in no-tillage rice fields at anexperimental site in Wuhan from 2009 to 2011. In the absence of PAC treatment, rapeseed sownin pots and rice fields showed excessive elongation of the crown, which resulted in low yieldsand yield-related traits at maturity. Soaking seeds in PAC improved seedling growth, seedlingsurvival and crown diameter, but decreased the crown length during winter. The most effectiveconcentration of PAC was 4 mg/L and higher concentrations significantly reduced seedgermination rates. Our results demonstrated that rapeseed sown in rice fields after the seeds hadbeen soaked with PAC improved seedling quality at the wintering stage and yield at maturity.

Impacts of some upland rice-based cropping systems on soil macrofauna abundance and diversity and black beetle damage to rice

Black beetles (BB: Heteronychus spp.: Coleoptera, Scarabaeidae) are serious constraints to upland rice production in the Madagascar central highlands. From 2002 to 2007 we compared the effects of two soil management and two fertilization modalities in an upland rice-based cropping system on soil macrofauna abundance, diversity and BB damage to rice crops and yield. This cropping system involved a 2-year rotation of upland rice the first year, followed by common bean the second year, with oat as a relay crop under both conventional tillage (CT) and no-tillage soil management (NT), each under both organic (OF) and mineral fertilization (MF). All four modalities (CT-OF; CT-MF; NT-OF and NT-MF) were managed under two plant protection levels (seed dressing with imidacloprid + thiram vs no seed dressing). Herbivorous/detritivorous beetles were the most abundant soil biota, respectively representing more than two-thirds and half of all macrofauna at the outset of the experiment and 4 years later, with the BB Heteronychus arator rugifrons (Fairmaire) being the dominant pest species (herbivore). The Shannon diversity index was reduced significantly between the beginning and the end of the experiment 4 years later, while it was only marginally affected by soil management, fertilization and seed dressing regimes at both sampling dates. Throughout the study period, seed dressing resulted in a significant reduction in BB damage, and in a significantly higher rice grain yield as compared to control. NT management did not enable seed dressing discontinuation based on grain yield and BB damage level after 3 and 4 years of this practice, respectively. In this respect, CT-MF management ranked best in the absence of seed dressing. The reasons for the poor performance of NT management in the studied cropping system as compared to the same strategy used in other systems reported in earlier studies are discussed.

Yield Potentiality of Maize as Relay Crop with T. Aman Rice under Different Agronomic Management

AbstractThe experiment was conducted at the Regional Agricultural Research Station, BARI, Ishwardi, Pabna, Bangladesh, during 2013-2014 and 2014-2015 to introduce maize as relay crop with T. Aman rice under different agronomic practices for determine the production potentials. The experiment was design split plot with three replications. The agronomic management practices included four plant spacing viz. S1=75 cm×20 cm (66666 plants/ha), S2=60 cm×20 cm (83333 plants/ha), S3=50 cm×20 cm (100000 plants/ha) and S4=40 cm×20 cm (125000 plants/ha) and four soil management practices viz. M1=soil mulching at 25 DAE, M2=earthing up at 25 DAE, M3=straw mulching at 25 DAE and M4= without earthing up and mulching (control). Seeds were relayed by dibbling manually in 10 days before the harvest of T. Aman rice. Results showed that an increasing plant spacing increased leaf area Index (LAI), total dry matter (TDM), crop growth rate (CGR) and light energy interception (LEI). Grain yield was higher in S3spacing (8.44 t/ha) than others (S48.11 t/ha, S27.34 t/ha and S16.89 t/ha). Among the soil management practices, M2increased LAI, TDM, CGR, LEI as well as grain yield. Moreover, M2and M1gave similar grain yield (8.22 t/ha and 8.02 t/ha), that were significantly greater than other two soil management practices (M37.55 t/ha and M46.98 t/ha). From the economic point of view, combination of S3M1gave better performance with gross margin of Tk. 95000/ha and BCR of 2.17. On the basis of results, S3M1combination was suitable for growing maize under relay sowing with T. Aman rice.

Relay cropping as a sustainable approach: problems and opportunities for sustainable crop production.

Climate change, soil degradation, and depletion of natural resources are becoming the most prominent challenges for crop productivity and environmental sustainability in modern agriculture. In the scenario of conventional farming system, limited chances are available to cope with these issues. Relay cropping is a method of multiple cropping where one crop is seeded into standing second crop well before harvesting of second crop. Relay cropping may solve a number of conflicts such as inefficient use of available resources, controversies in sowing time, fertilizer application, and soil degradation. Relay cropping is a complex suite of different resource-efficient technologies, which possesses the capability to improve soil quality, to increase net return, to increase land equivalent ratio, and to control the weeds and pest infestation. The current review emphasized relay cropping as a tool for crop diversification and environmental sustainability with special focus on soil. Briefly, benefits, constraints, and opportunities of relay cropping keeping the goals of higher crop productivity and sustainability have also been discussed in this review. The research and knowledge gap in relay cropping was also highlighted in order to guide the further studies in future.

Development of Sugarcane-cum-Potato Planter for Mechanisation of Simultaneous Planting of Sugarcane and Potato

Sugarcane and potato are the two major cash crops cultivated in the Indo-Gangetic plains of South Asia. Growing potato as intercrop with sugarcane has a synergistic effect on sugarcane, resulting in increased economic returns to farmers. In order to mechanise simultaneous planting of sugarcane and potato for intercropping, a new planting machinery named as sugarcane-cum-potato planter was designed and developed at ICAR-Indian Institute of Sugarcane Research, Lucknow, India. It was equipped with furrowers for opening of furrow and ridge making in between furrows, sett cutting unit for cane planting, potato seed tuber metering mechanism for potato planting, covering unit to cover planted sugarcane setts and potato and insecticide application unit. The designed equipment planted two rows of sugarcane in furrows and two rows of potato on ridges simultaneously in single pass. Picking and dropping of seed potato were automatic, whereas sugarcane seed stalk feeding for sett cutting was manual. Field testing of the developed planter was conducted at IISR farm in sandy loam soil. The effective field capacity of planter was 0.127 ha h−1. Average soil cover on sugarcane setts was 45 mm. Average depth of seed potato tuber placement on the ridges was 40 mm, and average tuber to tuber spacing was 192 mm. Developed machine-planted sugarcane at furrow spacing of 750 mm with average overlapping of 68 mm between the setts. The cost of planting operation with developed equipment was rupees 3160 ha−1 as against rupees 13,600 ha−1 in conventional planting. Saving in cost of planting operation was about 76% and labour about 90% with the developed planter as compared to conventional planting. Irrigation water use efficiency, yield attributes and total yield increased significantly in potato–sugarcane intercropping as compared to relay cropping of potato and sugarcane. Benefit/cost ratio in mechanised intercropping of potato and sugarcane with the developed planter was 2.57:1 followed by conventional manual intercropping (2.26:1) and manual potato–sugarcane relay cropping (1.84:1).

Enhancing Pulses Production in Bihar: Constraints and Strategies for Sustainable Growth

Food grains are the major agricultural commodity, produced on about 93 percent of cropped area, of which pulses share merely 7.06 per cent and the productivity of pulses ranges between 819 kg/ha in 2000-01 to 897 kg/ha in 2013-14. Bihar ranks 9th in terms of pulses production with a contribution of 0.52 million tons to the national pulse pool. Traditionally pulses have been considered important elements of cropping systems in the Bihar, but with the introduction of irrigation and high profitability of alternative sources of soil nutrients in the form of inorganic fertilizers in 1960s, pulses were replaced or relegated to marginal lands and were substituted by high- yielding varieties of rice and wheat. There has been an incessant decline in pulses area, production and productivity during last three and half decades accounting for about 437.24 thousand hectares, 428.93 thousand tons and 981 kg ha-1 respectively in 2014 - 15 against the corresponding figures of 717.2 thousand hectares, 620.7 thousand tons and 865 kg ha-1 in 2000-01 registering a compound annual decline of -2.5 percent in area and -0.41 percent in production but productivity increased by 2.15 percent per annum. Lentil is only crop which has performed well in Bihar whereas area and production of most of the major pulses have gone down. In Bihar 2.2 million ha rice fallow land is there which are most suitable for pulses cultivation where medium and long duration paddy is cultivated and after field vacating due to lack of irrigation facility and delay normally the field remains vacant. Post rainy season crop becomes difficult but in some areas relay cropping of small seeded lentil and lathyrus is done by broadcasting the seeds in the standing crop of rice 7-10 days before harvest when there is adequate moisture for germination and converting these mono-cropped areas into double cropped ones by pulses like moong, urd, and lathyrus can increase pulse production and sustain productivity of the rice-based system. There is need to popularize this system by developing varieties suitable for relay cropping and standardization of this agro-technology. Pulse production in Bihar is adversely affected by a number of biotic and abiotic stresses which can be overcome by assembling the available components of integrated pest management like host plant resistance, cultural practices to disrupt the life cycles of pests, and need-based use of pesticides and to validate them in farmers' participatory on-farm trial and demonstration in farmers field, to deliver management components effectively to stabilize and increase the productivity of pulses. There is also need to strengthen extension efforts to disseminate available pulse technologies through on-farm demonstrations and farmers' participatory research.

Relay intercropping and mineral fertilizer effects on biomass production, maize productivity and weed dynamics in contrasting soils under conservation agriculture

SUMMARYCash-constrained farmers who cannot afford herbicides and mineral fertilizers may incorporate green manure cover crops (GMCCs) as relay crops to aid in management of weeds and nitrogen in maize systems under conservation agriculture in cases where rotations are a challenge. An experiment was conducted at two sites with contrasting soil types, University of Zimbabwe farm (clay) and Domboshawa Training Centre (sandy) to investigate the effects of maize/velvet bean intercropping at 8 weeks after planting maize (WAPM), applying different fertilizer rates and exploring their interactive effects on weed composition, maize productivity and biomass production [total maize non-cob biomass (stover) plus GMCC biomass]. The performance of the system depended largely on the amount of rainfall received within and across the seasons, sites and their interaction; also on the amount of fertilizer applied. Generally, biomass yields attained by velvet bean [Mucuna pruriensL. (DC.)] were lower than reported previously. Maize grain yield and weed diversity were higher in treatments with higher fertilizer rates, reaching up to 5·1 t/ha and 1·39, respectively. Generally, the highest weed diversity and highest maize grain yield values were observed in maize/velvet bean combinations and higher fertilizer rates (i.e. 0·27 and 4·8 t/ha, respectively) in the sandy soil. Higher fertilizer rates resulted in greater maize stover yield and this contributed greatly to the biomass productivity of the system in the sandy soil in the 2012/13 season, while the high biomass productivity observed in velvet bean in the clay site in the final season contributed significantly to productivity. Maize productivity was not affected by velvet bean introduced at 8 WAPM in any of the seasons. The present study showed that relay cropping velvet bean as late as 8 WAPM and onwards has potential to increase biomass production without compromising maize yields. However, planting it as late as 8 WAPM results in reduced productivity due to reduced moisture availability.

Pulses Production in Bihar: An Overview of Constraints and Opportunities

Traditionally pulses have been considered important elements of cropping systems in Bihar, but with the introduction of irrigation and high profitability of alternative sources of soil nutrients in the form of inorganic fertilizers in 1960s, pulses were replaced or relegated to marginal lands and were substituted by high- yielding varieties of rice and wheat. Bihar ranks 9th in terms of production with a contribution of 0.52 million tons to the national pulse pool but shares only 7.06 per cent of total area under food grains, with productivity ranging between 819 kg/ha in 2000-01 to 897 kg/ha in 2013-14. There has been an incessant decline in pulses area, production and productivity during last three and half decades accounting for about 437.24 thousand hectares, 428.93 thousand tons and 981 kg ha-1 respectively in 2014 - 15 against the corresponding figures of 717.2 thousand hectares, 620.7 thousand tons and 865 kg ha-1 in 2000-01, registering a compound annual decline of -2.5 percent in area and -0.41 percent in production but productivity increased by 2.15 percent per annum. Lentil is only crop which has performed well in Bihar whereas area and production of most of the major pulses have gone down. About 2.2 million ha of rice fallows in Bihar, are most suitable for pulses cultivation. Also there are some indigenous practices like broadcasting pulses like moong, urad, and lathyrus in standing rice crop 7-10 days before harvest making full use of available moisture in the field can be promoted for converting mono-cropped areas into double cropped ones can help increase pulse production. There is also an urgent need to popularize this system by developing varieties suitable for relay cropping and standardization of this agrotechnology. The paper examines the current production and productivity scenario along with various factors affecting their performance both biotic and abiotic stresses. It also advocates the various strategies to improve the production and productivity by overcoming these constraints, in the state.

Salinity and High Temperature Tolerance in Mungbean [Vigna radiata (L.) Wilczek] from a Physiological Perspective.

Biotic and abiotic constraints seriously affect the productivity of agriculture worldwide. The broadly recognized benefits of legumes in cropping systems—biological nitrogen fixation, improving soil fertility and broadening cereal-based agro-ecologies, are desirable now more than ever. Legume production is affected by hostile environments, especially soil salinity and high temperatures (HTs). Among legumes, mungbean has acceptable intrinsic tolerance mechanisms, but many agro-physiological characteristics of the Vigna species remain to be explored. Mungbean has a distinct advantage of being short-duration and can grow in wide range of soils and environments (as mono or relay legume). This review focuses on salinity and HT stresses on mungbean grown as a fallow crop (mungbean-rice-wheat to replace fallow-rice-wheat) and/or a relay crop in cereal cropping systems. Salinity tolerance comprises multifaceted responses at the molecular, physiological and plant canopy levels. In HTs, adaptation of physiological and biochemical processes gradually may lead to improvement of heat tolerance in plants. At the field level, managing or manipulating cultural practices can mitigate adverse effects of salinity and HT. Greater understanding of physiological and biochemical mechanisms regulating these two stresses will contribute to an evolving profile of the genes, proteins, and metabolites responsible for mungbean survival. We focus on abiotic stresses in legumes in general and mungbean in particular, and highlight gaps that need to be bridged through future mungbean research. Recent findings largely from physiological and biochemical fronts are examined, along with a few agronomic and farm-based management strategies to mitigate stress under field conditions.

‘To Adopt or not to Adopt?’ Legume Adoption in Maize‐Based Systems of Northern Thailand: Constraints and Potentials

AbstractA considerable growth in the maize (Zea mays L.) sector in Southeast Asia has resulted in a rapid expansion and intensification of maize monoculture on sloping uplands. This practice entailed the heavy use of fertilisers, leading to environmental degradation and farmers' indebtedness. Intercropping of legumes with maize could complement or replace fertiliser inputs; however legume adoption by smallholder maize farmers remains low. This study investigates the constraints and potentials to integrate legumes in maize‐based cropping systems in such environments. A comparative study between maize monocropping and maize/legume relay cropping was carried out in two villages of Thailand, using surveys, participatory rural appraisal (PRA) tools and interviews. The results demonstrated that both cropping systems were equally profitable, although the maize yield in maize/legume relay cropping was lower than that in monocropping. Low selling price was the most cited reason by the non‐adopters for not introducing legumes. Selling price of legume grains, ease of harvesting, marketability and ease of growing were the four main criteria that determined the adopters' choice of legume species. Among the cultivated legumes, ricebean (Vigna umbellata L.) best fulfilled the criteria for the choice of legume species. Establishing maize/legume relay cropping as an alternative to maize monocropping under rainfed conditions can decrease risks, due to reduced expenses for farm inputs and similar economic returns. This study generated useful information for agricultural policy makers and development practitioners in identifying the barriers and facilitating factors that influence farmers' decision to adopt legumes and the conditions that shape the farmers' decision‐making environment. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of relay cover crop planting date on their biomass and maize productivity in a sub-humid region of Zimbabwe under conservation agriculture

Relay cropping of cover crops is a strategy of increasing biomass yields and productivity of maize-based systems. However, there is need to strategically plan the relay cropping to avoid competition between the main crop and the relay cover crops while at the same time obtaining optimum yields from both crops. A study was carried out in a clay soil in a sub-humid region of Zimbabwe to investigate the effect of introducing different relay cover crops at 8, 11 and 15 weeks after planting maize (WAPM) into a standing maize crop on biomass yield of the relay cover crops, their emergence and maize yields in the 2012–13 and 2013–14 seasons. From the results of the study, it was observed that the introduction of relay cover crops late in the season compromises their emergence and hence biomass yields (as low as 0.8kgha−1 for blue lupins (Lupinus angustifolius var. angustifolius (L.)). In a season where longer mid-season dry spells were experienced (2013–14), biomass yields of the relay cover crops were lower than in 2012–13 season. Delays in planting of relay cover crops (i.e. from 8 to 11 and from 11 to 15 WAPM) resulted in yield reductions of around 50%. Relay cover crops introduced at different periods of the season had no significant effects on maize grain and biomass yields. However, there are relay cover crops such as the velvet bean (Mucuna pruriens (L.) DC) and common oats (Avena sativa L.) that showed better emergence even in the sub-optimal conditions (with emergence as high as 90%). Of all the investigated relay cover crops, none could contribute to significant amounts of biomass thus insignificant increases in total plot biomass. There is need to investigate on other earlier planting dates that do not compromise the biomass productivity of such relay cover crops.

Effects of stubble length of rice in mitigating soil moisture stress and on yield of lentil (Lens culinaris Medik) in rice-lentil relay crop

Opportunity to utilize carry-over residual soil moisture to produce lentil crop in rice-fallows was one of the basic and strategic research objectives of the present experiment. Lentil (Lens culinaris Medik, variety B-77) was broadcasted upon two rice habits viz. short-duration (SD, 110days) and long-duration (LD, 140days) in the end of October and first fortnight of November during 2011–2012, 2012–2013 and 2013–2014 seasons, in a clay loam Inceptisol of the Gangetic alluvium of eastern India. Two stubbles heights, viz. short (10cm) and long (20cm) were kept as standing residues at the time of harvesting of rice. Late sown lentil with short stubble residues faced surface soil drying earlier than early sown lentil or late sown lentil with tall stubble residues. Tall stubble height contributes only 1–4% higher soil water during vegetative to flowering stages than short stubble height. Stress was experienced when soil moisture content in the root-zone reached <22% in this soil and such stress decreased the leaf relative water content (RWC). Retaining tall rice stubbles on the soil surface decreased daytime soil temperature by 9.4–14.6°C and modified the crop coefficient (Kc) by increasing transpiration and reducing evaporation, thereby maintaining higher leaf area index (LAI). The Kc values for the initial, development, mid and late season stages of lentil under relay cropping were 0.48, 0.54, 0.82 and 0.48, respectively, with short and tall standing stubble heights. Root length density (RLD) values increased at a faster rate in 200–400mm layer, especially in tall stubble than short. Soil moisture stress was negatively related (R2=0.66, P<0.05) to RWC, however, RLD maintained an asymptotic relationship with RWC. Actual evapotranspiration (ETa) of lentil amounted to 154.8mm and the ETa in broadcasted upon SD rice was 14% higher than ETa in LD rice. Lentil in tall stubbles amounted to 150.6mm ETa, which was 7% more than that in short stubbles. Yield of lentil broadcasted upon SD was 20% higher than 20days delay with LD rice, and tall stubbles produced 18% more yield than short stubbles. The water productivity (WP) of lentil under SD rice was only 6% higher than lentil in LD rice; however, tall stubbles produced 11% higher WP than short standing stubbles. Keeping stubbles height of SD or LD rice may be an efficient way of using the existing land and water resources for mitigating soil moisture stress and maintaining grain yield and water productivity of lentil relayed with short- and long-duration rice habits.