Cotton-wheat Cropping System Research Articles

Emitter spacing, depth of lateral placement, and nutrient levels affect productivity of cotton-wheat cropping system under sub-surface drip fertigation

This comprehensive two-year field study investigates the transformative potential of sub-surface drip fertigation (SSDF) as a sustainable alternative to traditional surface flood irrigation coupled with manual nutrient broadcasting in the cotton-wheat cropping system (CWCS). The field experiment was laid out in a split-plot design with combination of two lateral depths (25±2.5 and 30±2.5 cm) and two emitter spacings (30 and 40 cm) in main plots and four fertigation schedules [100% Recommended nitrogen (RDN)-112.5 kg N ha−1) and 125%RDN in 10 &14 equal splits (cotton); 100% Recommended nitrogen and phosphorus (RDNP)-125:62.5 kg NP ha−1) and 80%RDNP in 08 & 10 equal splits (wheat)] in sub plots.Two additional control treatments i.e., C1[Surface flood (SF) irrigation with 100%RDN (105 kg N ha−1 for cotton), 100%RDNP (125:62.5 kg NP ha−1for wheat) applied through manual broadcasting] and C2[SSDF at 20±2.5 cm depth, 20 cm emitter spacing, and 100%RDN for cotton(112.5 kg N ha−1) in 10 equal splits, and 80%RDNP for wheat (100:50 kg NP ha−1) applied in 8 equal splits] were also studied.Results revealed an 18.6% improvement in CWCS productivity under SSDF, when cotton and wheat were fertigated with 125%RDN in 14 equal splits and 100%RDNP in 10 equal splits, respectively in comparison to 100%RDN in 10 equal splits (cotton) and 80%RDNP in 08 equal splits (wheat). Furthermore, lateral placement (25±2.5 cm) depth with emitter spacing (30 cm), and fertigation [125%RDN in 14 equal splits (cotton) and 100%RDNP in 10 equal splits (wheat)] improved crop, irrigationand total water productivity indices by 1.3, 3.1, and 2.1 folds, respectively as compared to SF (C1). Moreover, improvednet returns by 18.7–52.0%was also evident with a SSDF of 100%RDN in 14 equal splits and 80%RDNP in 10 equal splits in cotton and wheat.These findings elucidated that SSDF with drip lateral placement at 25±2.5 cm depth, having an emitter spacing of 30 cm, and fertigation of 125%RDN (140 kg N ha−1) in 14 equal splits(cotton); 100%RDNP (125:62.5 kg NP ha−1) in 10 equal splits (wheat) could be a novel water-savvy concept in sustaining the yield and water productivity of cotton-wheat cropping system under arid agro-ecosystems.

Optimizing crop water productivity and delineating root architecture and water balance in cotton–wheat cropping system through sub-surface drip irrigation and foliar fertilization strategy in an alluvial soil

Water-intensive agricultural practices in tandem with conventional irrigation methods such as flood irrigation, has caused severe water scarcity in south-Asian Indo-Gangetic Plains (IGPs). The adoption of micro-irrigation systems (sprinker, surface drip and sub-surface drip) instead of flooding offers a great promise in water saving and enhanced fertilizer-use efficiency, and thus, improved productivity. The change in irrigation and fertilization methodology may affect the behavior of plant root growth, root architecture and, crop and water productivity. Hence, current study aimed at evaluating the influence of sub-surface drip-irrigation and fertigation strategy on crop and water productivity besides delineating root architecture and soil water balance in cotton–wheat cropping system (CWCS). Results showed that sub-surface drip irrigation (SSDI) enhanced the root system by stimulating the development of new secondary roots which actively participated in physiological responses. Root length at boll opening stage of cotton increased significantly under SSDI at 60% ETc (60% of evapo-transpiration) over other treatments. Root mass density in wheat was also significantly higher under SSDI particularly at 15–30 cm depth over surface drip and flood irrigation during 2020–21. SSDI at 100% ETc (100% of evapo-transpiration) produced statistically similar seed cotton yield, wheat grain yield and the system productivity (wheat equivalent yield) to 80% ETc. SSDI at 80% ETc (80% of evapo-transpiration), resulted in water-saving of ∼43.2% over flood irrigation in CWCS. Further, fertigation through SSDI resulted in ∼20% reduction in fertilizer needs, while achieving the yield equivalent to that of conventional fertilization. Irrigation water productivity and bio-physical water productivity of this system were ∼46.1 and 5.7% higher under 80% ETc along with F80 (80% recommended dose of nitrogen, RDN) and Mfoliar (foliar application of KNO3 & MgSO4 at flower initiation and boll development stages of cotton) over flood irrigation. Overall, SSDI at 80% of evapo-transpiration along with 80% RDN and foliar application of KNO3 & MgSO4 may prove highly beneficial to enhance the crop and water productivity in CWCS, besides saving irrigation water-use by ∼43.2% over flood irrigation in water-scarce agro-ecologies of south-Asia.

Acidified manure and nitrogen-enriched biochar showed short-term agronomic benefits on cotton–wheat cropping systems under alkaline arid field conditions

Application of organic residues such as farm manure and biochar in various agricultural environments have shown positive effects on soil carbon sequestration. However, there is a lack of consensus regarding the agronomical benefits of a single and small dose of biochar and farm manure in arid alkaline soils. Therefore, a field experiment with the given treatments (1) control (no amendment), (2) acidified manure (AM) at 300 kg ha−1, (3) nitrogen (N) enriched biochar (NeB) at 3 Mg ha−1, and (4) an equal combination of AM + NeB (150 kg ha−1 AM + 1.5 Mg ha−1 NeB)) was conducted in a typical cotton–wheat cropping system. A parallel laboratory incubation study with the same amendments was carried out to account for soil carbon dioxide emission (CO2). The N enrichment of biochar and its co-application with acidified manure increased soil mineral N (NO3− and NH4+) in the topsoil (0–15 cm), and increased total N uptake (25.92% to 69.91%) in cotton over control, thus reducing N losses and increased uptake over control. Compared to the control, co-application of AM + NeB significantly improved soil N and P bioavailability, leading to increased plant biomass N, P, and K (32%, 40%, 6%, respectively) uptake over control. The plant's physiological and growth improvements [chlorophyll (+ 28.2%), height (+ 47%), leaf area (+ 17%), number of bolls (+ 7%), and average boll weight (+ 8%)] increased the agronomic yield in the first-season crop cotton by 25%. However, no positive response was observed in the second season wheat crop. This field study improved our understanding that co-application of acidified manure and N-enriched biochar in small dose can be a strategy to achieve short-term agronomic benefits and carbon sequestration in the long run.

Assesment of Boron in Soil, Plant and Irrigation Water under Cotton-wheat Cropping System of Northern India

Background: The use of high yielding varieties, high analysis fertilizers and intensive cultivation has depleted the fertility of soils particularly with respect to micronutrients. The deficiency of B is expected to be high in coarse-textured soils having low organic matter, high CaCO3 and high pH. Methods: Geo-referenced surface (0-15 cm, n=155) soil samples, cotton leaves at pre flowering stage (n=75), wheat flag leaves (n=80) and tube well water (n=75) samples were collected from Bathinda, Mansa and Mukatsar districts of Punjab. Result: About 5, 18 and 20 per cent of soil, cotton and wheat samples were deficient in B, respectively. Hot water soluble B in soil was significantly positively correlated with pH (r= 0.230*), ESP (0.680**), B concentration in leaves of cotton (r=0.259*) and wheat (r=0.531**) but negatively with CaCO3 in soil (r= -0.210*). About 40 per cent of tubewell waters had greater than 2.0 mg B l-1. On an average, one cm ha of tube well water may add up to 93g B ha-1 to soil.

Reduced tillage and subsurface fertigation improve productivity and economic benefits in the cotton-wheat cropping system

Soil compaction under repetitive tillage and surface flood method of irrigation (SFMI) are significant hurdles for sustaining crop production in India, necessitating the adoption of efficient soil and water management strategies. Hence, a 3-year field study was conducted at two diverse agro-climatic locations (Abohar and Faridkot) to investigate the impact of subsurface drip (SUSD) fertigation on crop and water productivity of cotton-wheat cropping system (CWCS), over traditional practice (TP) (conventional tillage with SFMI and manual application of nutrients). The experiment was conducted in a factorial randomized complete block design with three levels of subsurface drip irrigation (SUSDI) [100, 80, and 60% of crop evapotranspiration (ETc)] and two fertigation levels [75% recommended dose of nutrients (RDN) and 100% RDN], where TP and surface drip (SD) fertigation at 80% ETc coupled with 100% RDN (Control 2), served as two control treatments. Cotton was raised through reduced tillage, while zero till drill was used for sowing wheat. The results revealed that, barring SUSDI at 60% ETc, both crops exhibited improved yield under all drip combinations of reduced or zero tillage over TP. Better mass and higher length of cotton roots in drip fertigation were evident due to improved steady-state infiltration rates (SSIR) and reduced bulk density (BD) under conservation tillage. When 100% RDN was applied, the 100% and 80% ETc SUSDI resulted in 26.7% and 24.7% higher seed cotton yield (SCY) than TP. Similarly, wheat yield with 100% RDN was improved by 10.5% and 14.4% under SUSDI of 80% and 100% ETc, respectively, over the TP. The results indicated that SUSD can be clubbed with reduced tillage for better soil health, improved crop yield, and higher apparent water productivity. The improved benefit to cost (B:C) owing to enhanced monetary returns over TP also substantiated that reduced tillage with SUSD is a viable and remunerative practice for CWCS. The study elucidated that reduced tillage exercised a beneficial effect on physical soil properties by lowering BD and improving SSIR. At the same time, SUSD could save huge amounts of irrigation water besides enhanced input use efficiency leading to higher crop productivity.

Pathway analysis of food security by employing climate change, water, and agriculture nexus in Pakistan: partial least square structural equation modeling.

Increasing population and augmented demand for food have put burden on water resources, crops, and livestock for future sustainability. Pakistan is facing difficulties of water shortage, low crops and livestock productivity, meagre livelihood, and intensive food insecurity. Hence, this study was conducted in Pakistan to explore the nexus of climate change, irrigation water, agriculture, rural livelihoods, and food security. The study is based on primary data of 1080 farmers gathered from 12 districts of the rice-wheat and cotton-wheat cropping systems. A partial least square structural equation modeling (PLS-SEM) was used to compute the nexus. Findings of path analysis indicated that climate change had a significant negative impact on irrigation water, crops, livestock, rural livelihood, and food security in both cropping systems. There was positive relationship between surface water and crops. In addition, groundwater and crops were also positively and significantly correlated. The impact of crop was positive and significant on rural livelihood and food security. Furthermore, rural livelihood and food security were positively and significantly influenced by livestock. Moreover, there was positive relationship between rural livelihood and food security. The cotton-wheat cropping system was more affected by climatic and natural hazards than rice-wheat cropping system. Interconnectivity among nexus components and their contribution to rural livelihood and food security indicate that government, policymakers, and other concerned stakeholders should effectively improve food security policies under climatic and natural hazards. Moreover, it helps in examining adverse impacts of hazards induced by climate change on nexus components, leading to the designing and adoption of sustainable climate change policies. The study's originality lies in its ability to provide a inclusive and integrated pathway of the interconnections and interdependencies among these variables, identifying key drivers of food insecurity in Pakistan. Moreover, outcome of the study has policy implications for developing sustainable policies and strategies to improve sustainable food security in the country.

Energy budgeting and productivity response of cotton-wheat cropping system to mechanical sub-soiling

ABSTRACT In North India, sub-soiling is required to alleviate the problem of soil compaction raised due to the use of heavy machinery. We have emphasized energy auditing to understand the practical feasibility of sub-soiling in cotton-wheat cropping system. Four sub-soiling treatments (cross and single side sub-soiling at 1.0 m, 1.5 m under both cases) in addition to conventional tillage were compared with conventional tillage alone at two sites. Sub-soiling improved crop yield by 13.5–33.7% in cotton and 13.0–22.0% in wheat as compared to control. Net monetary returns earned with sub-soiling were 98–408 and 159–287 US$/ha higher under cotton and wheat, respectively over control. Energy auditing suggested that sub-soiling treatments consumed 489–1504 MJ/ha extra energy in cotton season, however, net energy gain was higher in cotton (by 11,518–29,715 MJ/ha) and wheat (by 19,861–32,594 MJ/ha) over control. Energy use efficiency was higher under sub-soiling treatments in cotton (5.36–7.25) and wheat (9.55–10.46), whereas corresponding values under control were 4.64–6.18 and 8.18–8.36. Similarly, lesser specific energy was observed under sub-soiling treatments as compared to control. The present study concluded that sub-soiling increased cotton productivity and energetic returns as well as had the significant residual effect on wheat crop. These results clearly suggest that sub-soiling is a sustainable practice for cotton-wheat system in north-western India.

Do farmers' risk perception, adaptation strategies, and their determinants benefit towards climate change? Implications for agriculture sector of Punjab, Pakistan.

Due to global and regional climatic dynamics for a couple of decades, agricultural productivity, rural livelihood, and food security have been badly affected in Pakistan. This study was conducted in Punjab, Pakistan, to explore the farmers' understanding of the impacts of climate change, adaptation strategies, determinants, and benefits on agriculture using data from 1080 respondents. Perceived risks by the farmers in the rice-wheat cropping system and the cotton-wheat cropping system were weed infestation, seed rate augmented, low-quality seeds, infestation of crop diseases and pests, change of cropping pattern, increase of input use, decrease of cropping intensity and productivity, decreasing soil fertility, increasing irrigation frequency, and increase of harvesting time. To alleviate the adverse influences of climate change, the adaptation strategies used by farmers were management of crop and variety, soil and irrigation water, diversification of agriculture production systems and livelihood sources, management of fertilizer and farm operations time, spatial adaptation, access to risk reduction measures and financial assets, adoption of new technologies, institutional support, and indigenous knowledge. Moreover, the results of Binary Logistic Regression indicate that adaptation strategies are affected by different factors like age, education, household family size, off-farm income, remittances, credit access, information on climatic and natural hazards, information on weather forecasting, land acreage, the experience of growing crops and rearing of livestock, tenancy status, tube well ownership, livestock inventory, access to market information, agricultural extension services, and distance from agricultural input/output market. There is a significant difference between adapters and nonadapters. The risk management system may be created to protect crops against failures caused by extreme weather events. There is a need to develop crop varieties that are both high yielding and resistant to climate change. Moreover, cropping patterns should be revised to combat the effects of climate change. To enhance farmers' standard of living, it is necessary to provide adequate extension services and a more significant number of investment facilities. These measures will assist farmers in maintaining their standard of living and food security over the long term to adapt to the effects of climate change based on various cropping zones.

Modelling wellbeing of farmers by using nexus of climate change risk perception, adaptation strategies, and their drivers on irrigation water in Pakistan.

This study aimed to determine the farmers' perceived impact of climate change on irrigation water and the adaptation measure adopted to mitigate its adverse effects. A binary logistic regression model was used to identified factors affecting the selection of adaptation measures. Partial Least Square-Structural Equation Modelling (PLS-SEM) was employed to compute the benefits of adaptation strategies. The study was conducted in two major cropping systems, i.e., the Cotton Wheat Cropping System (CWCS) and Rice Wheat Cropping System (RWCS) of Punjab, Pakistan, using primary data of 1080 farmers collected through a multistage sampling technique. Due to climate change there was deterioration in surface water and groundwater quality in CWCS than in RWCS. The farmer uses different adaptation strategies like water harvesting, crop diversification, increasing use of irrigation, laser land leveling to save water, making ridges, building a water harvesting scheme, changing irrigation time, high-efficiency irrigation system and water-saving technologies. Adaptation strategies used by farmer were affected by different socioeconomic, demographic and agronomic factors. Results of the binary logistic regression showed that age, farming experience, education, household size, farm size, tenancy status of owner, access to farm credit, information on weather forecasting, soil quality, tube well ownership, remittances, off-farm income, agricultural extension services provided for irrigation water, and information on climatic and natural hazards played a significant role in the selection of adaptation strategies for irrigation water. Results of PLS-SEM showed that adaptation strategies mitigate the adverse effects of climate change on irrigation water. Farmers' awareness regarding the impact of climatic variability on irrigation water should be enhanced. Availability of credit to farmers should be improved on easy terms to facilitate the adoption of interventions for better irrigation water management. It is high time for policymakers to design effective, affordable, and workable policies to mitigate climate change vulnerabilities against irrigation water to improve the wellbeing of the farmers.

Phenotypic characterization of wheat germplasm for heritability and dissection of association among post anthesis traits under variable sowing dates

BackgroundThe world's main crop for producing staple foods is wheat. In South Asia's cotton-wheat cropping system, however, a late cotton harvest causes a delayed wheat planting, which causes significant production losses. Therefore, this study investigated genetic diversity among wheat genotypes for late sowing. Additionally, associations between several yield-related parameters were discovered, along with their direct and indirect implications on the choice of the best genotypes suitable for late planting. MethodsTwenty wheat genotypes/advance lines were evaluated under two sowing times, i.e., normal sowing and late sowing for two consecutive years (2019–2021). Data regarding post anthesis traits were collected. ResultsThe findings showed that planting dates and genotypes substantially (p < 0.05) impacted all characteristics. Genotype ‘9622’ proved consistent for grain yield by showing the lowest reduction under late sowing. Similar to this, assessments of heritability, correlation, and path coefficients showed that heredity and association strength varied with various sowing dates. Number of spikelets per spike, spike length and biological yield showed the highest correlation and direct and indirect effects on grain yield. Association among traits, and the performance of different genotypes under normal and late sowing was also confirmed by biplot analyses, which grouped the genotypes based on their variation for different traits. ConclusionIn conclusion, late sowing reduced yield and changed association among the studied traits, probably due to terminal heat stress. Therefore, selection criteria must be evaluated separately in selecting genotypes adoptable to late sowing and other varying environmental conditions.

Influence of Transgenic (Bt) Cotton on the Productivity of Various Cotton-Based Cropping Systems in Pakistan

Cotton (Gossypium hirsutum L.) is an important fiber crop in Pakistan with significant economic importance. Transgenic, insect-resistant cotton (carrying a gene from Bacillus thuringiensis (Bt)) was inducted in the cotton-based cropping systems of Pakistan during 2002, and is now sown in &gt;90% of cotton fields in the country. However, concerns are rising that Bt cotton would decrease the productivity of winter crops (sown after cotton), leading to decreased system productivity. This two-year field study determined the impacts of transgenic (Bt) and non-transgenic (non-Bt) cotton genotypes on the productivities of winter crops (i.e., wheat, Egyptian clover, and canola), and the overall productivities of the cropping systems including these crops. Four cotton genotypes (two Bt and two non-Bt) and three winter crops (i.e., wheat, Egyptian clover, and canola) were included in the study. Nutrient availability was assessed after the harvest of cotton and winter crops. Similarly, the yield-related traits of cotton and winter crops were recorded at their harvest. The productivities of the winter crops were converted to net economic returns, and the overall economic returns of the cropping systems with winter crops were computed. The results revealed that Bt and non-Bt cotton genotypes significantly (p &lt; 0.05) altered nutrient availability (N, P, K, B, Zn, and Fe). However, the yield-related attributes of winter crops were not affected by cotton genotypes, whereas the overall profitability of the cropping systems varied among the cotton genotypes. Economic analyses indicated that the Bt cotton–wheat cropping system was the most profitable, with a benefit–cost ratio of 1.55 in the semi-arid region of Pakistan. It is concluded that Bt cotton could be successfully inducted into the existing cropping systems of Pakistan without any decrease to the overall productivity of the cropping system.

EFFECT OF SEEDING RATE AND SEED SOAKING DURATION ON PRODUCTIVITY OF RELAY- INTERCROPPED WHEAT IN COTTON

&#x0D; &#x0D; &#x0D; The major problem in cotton-wheat cropping system is delayed harvesting of cotton which results in late planting of wheat. Therefore, a field experiment was conducted on relay wheat in standing cotton that comprised of three different seeding densities (100, 125 and 150 kg ha-1) and four seed soaking durations (0, 6, 12 and 18 hours). The experiment was designed in randomized complete block design with factorial arrangement having three replications. The interactive effect of seed rates and seed soaking duration on emergence count, leaf area index, spikelet’s per spike, grains per spike and grain yield were significant. Wheat sown with seed rate of 150 kg ha-1 and 12 hrs of seed soaking produced significantly higher yield than all other combinations except for 125 kg ha-1seed rate and 12 and 18 hrs of seed soakings. In conclusion, the productivity of relay wheat in standing cotton can be enhanced by using seed rate of 150 kg ha-1 along with seed soaking duration of 12 hours.&#x0D; &#x0D; &#x0D;

Moisture and nutrient management strategies influence the photo-thermal environment in cotton-wheat cropping system

Moisture and nutrient management strategies influence the photo-thermal environment in cotton-wheat cropping system

FARMER’S PERCEPTIONS REGARDING NATURAL HAZARDS IN COTTON-WHEAT CROPPING SYSTEM OF PUNJAB, PAKISTAN

The present research study was conducted during 2020 in Institute of Agricultural Resource Economics, University of Agricutlure, Faisalabad, Punjab, Pakistan to measure the farmers’ understanding regarding the impact of Climatic and Natural Hazards (CNHs) in the CottonWheat Cropping System of Punjab, Pakistan. The study also ranked the impact of climatic and natural hazards. The primary data were collected from 540 farmers of Punjab, Pakistan’s major cotton-growing districts. Questions regarding CNHs were inquired by using the Likert Scale (one being the strongly disagree and five strongly agree). Using descriptive statistics, the influence of climate and natural risks on agricultural yield was assessed. The replies were grouped into percentages and graphs. Approximately 61% of farmers strongly agreed that floods and droughts reduced agricultural yield. Moreover, 56% of respondents strongly agreed that frost, hailstorms and excessive heat harm agricultural output. In addition, 65 percent strongly agreed that biological illnesses, extreme cold, winter and summer winds, fog, smog, heatwaves, humidity, typhoons, and insect infestations had negative consequences. The impact of frequent rain was ranked as first by the farmers. In contrast, biological illnesses, hailstorms, bug infestations, floods and droughts, late rains, intense heat and frost, summer and winter wind storms, typhon, early showers and extreme cold were ranked 2nd through 17th. It was concluded that majority of farmers well aware of the climatic and natural hazards. Educating farmers on the impacts of CNHs on agricultural productivity was proposed.

Validation of medium range weather forecasts and its economic impact on cotton-wheat cropping system in South-Western Punjab

The value-added medium range weather forecast, received from Meteorological Centre, Chandigarh was validated using actual data taken from Agro-meteorological observatories of Bathinda and Faridkot, districts of Punjab during 2013-14 to 2017-18. Moreover, to study the economic impact of the forecast, field experiments were conducted during Rabi 2016-17 on wheat and Kharif 2017 on cotton having two sowing time and two management levels as adoption and non-adoption of agromet advisory services with four replications. Result revealed that, among the years and seasons, maximum accuracy was found with rainfall forecast, while, least correctness of the forecast was observed with wind speed. Except temperature, higher accuracy was observed during pre-monsoon season for all weather parameters. Alternatively, seasonal usability of forecast of rainfall, cloud cover, Tmax, Tmin and wind speed were found success ranged from 87-98%, 65-75%, 51-72%, 56-67% and44-83%, while, early usability was ranged 93-96%, 63-73%, 45-70%, 56-70% and 35-87%, respectively among study locations. Moreover, among study locations, the whole year RMSE was observed in the range from 3.95-5.12 mm, 2.71-2.80 Okta, 2.83-2.85 °C, 2.39-2.51 °C and 5.79-7.47 kmph, while, the value of correlation coefficient ranged from 0.68-0.83, 0.39-0.44, 0.92-0.93, 0.95-0.96 and 0.35-0.43 in respect of rainfall, cloud cover, maximum temperature, minimum temperature and wind speed, respectively. Moreover, adopted agro-meteorological advisory services (AAS) was found valuable, in which, better yield and its attributes were observed over non-adopted AAS for both the crops and study locations. Furthermore, an additional net return of Rs. 4055 and Rs. 1900 per acre for cotton, while, Rs. 5461 and Rs. 5045 per acre for wheat crop were obtained with the use of adopted AAS for timely and late sown conditions, respectively. On the other hand, adopted AAS showed 17 % and 21 % higher net profit for cotton and 26 % and 18 % higher net profit for wheat with timely and late sown crop, respectively.

Water footprint assessment of surface and subsurface drip fertigated cotton-wheat cropping system – A case study under semi-arid environments of Indian Punjab

The advanced methods of irrigation and nutrient supply may save huge quantity of costly inputs over the prevalent practice of surface flood (SF) irrigation and fertilizer broadcasting in Indian Punjab. Surface drip fertigation (SDF) and subsurface drip fertigation (SSDF) enables the combined application of fertilizer and irrigation for improving the input use efficiency in Cotton-Wheat cropping system (CWCS) over the SF. Though, both SDF and SSDF perform better than SF, but their suitability in reducing the water footprint (WF) of CWCS has been least assessed. Therefore, a 2 yr field study at two distinct agro-climatic zones has been conducted to quantify and compare the WF of SDF and SSDF in comparison to SF for CWCS under semi-arid environments. Results revealed that under SSDF, cotton and wheat crops consumed 32 and 37% lower water than respective SF, indicative of huge water saving over the prevalent practice. Contribution of green, blue and grey components towards total WF under SF was 42, 48 and 10% respectively for cotton, and 24, 59 and 18% for wheat. SSDF application at 80% crop evapotranspiration (ETc) along with 100% recommended dose of nitrogen remarkably reduced the WF without any yield loss for CWCS. Higher total WF for CWCS under SF (5.30 m³ kg⁻1) revealed it to be inferior as compared to SDF (3.71 m³ kg⁻1) and SSDF (3.52 m³ kg⁻1). Cotton alone consumed 65–78% of WFtotal of the CWCS, while the remaining 22–35% was attributed to wheat. A lowered WFtotal for CWCS under SDF and SSDF over that of SF elucidated them to be immensely helpful to conserve limited water resources under semi arid climates. A cropping system based assessment was much reliable option to obtain a clear indicator about the annual WF as compared to single crop based estimation. These results could be utilized to access the performance of alternative irrigation and cultivation systems for developing the WF reduction approach over extended geographical scale.

Retraction: Relay cropping of cotton in wheat improves productivity of cotton-wheat cropping system.

Retraction: Relay cropping of cotton in wheat improves productivity of cotton-wheat cropping system.

Relay cropping of cotton in wheat improves productivity of cotton-wheat cropping system.

Cotton-wheat (CW) is an important cropping system in Pakistan; however, delayed cultivation of cotton after wheat significantly deceases system productivity. Late-sown cotton crop suffers from heat stress, high fruit shedding and infestation of various pests and cotton leaf curl virus (CLCV). Therefore, early sowing of cotton is preferred to overcome these challenges. However, cotton planting is overlapped with the harvesting of wheat crop in CW cropping system. Since fallow land is unavailable, relay intercropping of cotton in wheat crop seems a viable option for early planting. This three-year field study evaluated the role of relay cropping of cotton in improving the productivity of CW cropping system and lowering CLCV infestation. Wheat was planted in 22.5 cm rows with no row skipped (W1), one row skipped after every three (W2), and six rows (W3) for planting cotton in 0.75 and 1.50 m apart rows. Early cotton was planted in fallow land (C1) and standing wheat in 0.75 (C2) and 1.50 m (C3) apart rows and conventional planting after wheat harvesting (C4). Yield losses of wheat crop ranged from 8.16 to 19.81% in W3 and W2, respectively compared W1. However, C2 and C3 treatments improved cotton yield by 86.07% and 64.89% suppressed CLCV infestation by 68.14% and 65.86%, respectively compared to C4. Moreover, net benefits from relay cropping (W2C2) were 2190.1 $ ha-1 in 2013–14, 1954.4 $ ha-1 in 2014–15 and 2559.5 $ ha-1 in 2015–16 in comparison with C1 (1543.5, 1311.7 and 1892.3 $ ha-1 during 2013–14, 2014–15 and 2015–16, respectively). The W2 resulted in higher cotton yield compared to W3 which is mainly attributed to double number of cotton rows in W2 than W3. It is concluded that cotton relay cropping (W2C2) resulted in the highest economic returns with minimum CLCV infestation. Therefore, W2C2 is recommended for improving the system productivity of CW cropping system.

Physical and chemical stabilization of soil organic matter in cropland ecosystems under rice–wheat, maize–wheat and cotton–wheat cropping systems in northwestern India

This article examines the impact of rice–wheat, maize–wheat and cotton–wheat cropping systems on total (TOC), labile and stable organic carbon (C) pools, aggregate stability and distribution of organic C in different size aggregates and the mineral fraction (silt + clay) of soil. The rice–wheat soils had significantly (p < .05) lower TOC concentration (4.46 ± 0.15 g C kg−1) compared with the other two cropping systems. Similarly, water-extractable organic C (WEOC, ∼0.48% of TOC), hot-water-soluble C (HWC, ∼5.5% of TOC) and microbial biomass C (MBC, ∼4.2% of TOC) were significantly lower in soils under rice–wheat compared to the other systems. The formation of water-stable aggregates (WSA) was related to the silt + clay (<0.053 mm) fraction of soils. As the silt + clay fraction increased, the proportion of macro-aggregates (>0.25 mm) increased with a concomitant decrease in the proportion of micro-aggregates (<0.25 mm). The carbon preservation capacity (CPC) of macro-aggregates (CPCMacA), micro-aggregates (CPCMicA) and total water-stable aggregates (CPCWSA) was significantly lower in rice–wheat soils compared with the other systems. The CPCMacA, mineral (silt + clay)-associated C (MinAC) and sodium hypochlorite oxidizable C (NaOCl-C) increased with an increase in the proportion of macro-aggregates and the mineral fraction of soils. A linear increase in the stable C pool ((silt + clay)-C and NaOCl-C) and soils’ silt + clay content implies that soils’ fine fraction was the principal mechanism of textural control on soil organic matter (SOM) stabilization.

Crop and water productivity, energy auditing, carbon footprints and soil health indicators of Bt-cotton transplanting led system intensification

Direct-seeded-cotton (DSC) leads to low crop and water productivity and energy-output with higher carbon-footprints besides impairing system-intensification under conventional cotton-wheat cropping system (CWCS). Hence, we evaluated two methods of Bt-cotton establishment [transplanted cotton (TPC) & DSC)] at three planting geometries/densities in four Bt-cotton based cropping-systems [DSC-wheat (DSC-W), TPC-wheat-mungbean (TPC-W-M), DSC-onion (DSC-O), TPC-onion-fodder cowpea + fodder maize (TPC-O-FC + FM)] in semi-arid region of south Asia. Poly-glass nursery-raised TPC exhibited significantly higher germination (96.5%), seedling-survival (96.1%) and 14.1% higher plant-stand owing to lower seedling-mortality (3.2%). TPC used ∼60% less irrigation-water but exhibited significantly higher seed-cotton, seed and lint yield, net-returns, radiation-use-efficiency and water-productivity by 11.4, 9.9, 14.3, 17.3, 10.7 and 260.6%, respectively over DSC. Planting geometry/density of 60 × 45 cm (37,037 plants ha−1) exhibited significantly higher crop and water productivity and economic-returns. Bt-cotton transplanting led system-intensification enhanced the system-productivity (26.1%), profitability (30.5%), water-productivity (19.3%) and land-use-efficiency (8.5%) over the DSC-based systems with significantly higher values under TPC-O-FC + FM. Energy-use pattern reveled that farm inputs viz. Fertilizers (54–60%), water (15–25%) and diesel (6–10%) consumed bulk of the input-energy in different cropping systems with greatest values under TPC-O-FC + FM. TPC-W-M exhibited highest system energy-output (604.6 × 103 MJ ha−1) and energy-returns (566.2 × 103 MJ ha−1). TPC-O-FC + FM exhibited significantly higher carbon-consumption (668.9 kg CE ha−1) and carbon-output (21431.3 kg CE ha−1) while maintaining significantly higher carbon-efficiency (32.0) and carbon sustainability index (31.0). TPC-O-FC + FM had least carbon-footprints (0.07 kg CE kg−1 SCEY) while conventional-CWCS exhibited 2-folds higher carbon-footprints. Legume-imbedded TPC-based cropping systems markedly increased the soil physical (bulk-density, water-stable-aggregates), chemical (SOC, available-NPK) and biological properties (soil-microbial-biomass-carbon, dehydrogenase and ergosterol activity) over the conventional CWCS and DCS-O systems. Overall, Bt-cotton transplanting led system-intensification upholds great importance in enhancing the system crop and water-productivity, profitability, energy-productivity, resource-use-efficiency and soil-health with minimal carbon-footprints in semi-arid agro-ecosystems of south Asia.