75 research outputs found
Performance of intercropping in pre-bearing mango orchards under drip irrigation in a degraded land
A field experiment was carried out to evaluate the performance of pre-bearing mango plantation with different intercrops (papaya, pineapple and combination of papaya and pineapple) in a sandy clay loam soil on a degraded land under drip irrigation at ICAR-Indian Institute of Water Management, Bhubaneswar, Odisha during 2017-18. Different intercrops planted in the mango (cv. Amrapali) were (i) two rows of papaya (cv. Red lady) in either side of mango plants, (ii) two paired rows of pineapple (cv. Queen) in either side of mango plants and (iii) one row of papaya and one paired row of pineapple in either side of mango plants with and without paddy straw mulch. All plants were irrigated by drip irrigation (DI) system. The amount of water used in mango–papaya cropping system (1220 mm) was higher than that in mango-pineapple cropping (975 mm). The volumetric soil water content in top 0.60 m soil in mango, papaya and pineapple were 20-23%, 21-24% and 22-24%, respectively. The vegetative growth parameters (plant height, canopy diameter and trunk girth) of young mango plants were not affected significantly either by papaya or pineapple intercropping. Straw mulch enhanced the growth parameters of mango plants by 8-12%. Similarly, growth parameters of papaya and pineapple were not affected significantly either by intercrops or by straw mulch. The highest yield (17.5 t/ha) and water productivity (21.1 kg/ha.mm) were observed in mango–pineapple system with straw much. The net profit from pineapple intercropping with straw mulch was highest (Rs. 140000/ ha) with benefit-cost ratio of 1.67, followed by papaya-pineapple intercropping with straw mulch in mango. Overall, the study reveals that mango intercropped with pineapple under drip irrigation with rice straw mulch can be practiced in pre-bearing mango orchards of Eastern India
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Not AvailableBackground Rising food demand, slowing productivity growth, poor N-use efficiency in rice, and environmental degradation necessitate the development of
more productive, environmentally-sound crop and soil
management practices. The system of rice intensification (SRI) has been proposed as a methodology to
address these trends. However, it is not known how
its modified crop-soil-water management practices affect efficiency of inorganic nitrogen applications.
Methods Field experiments investigated the impacts of
SRI management practices with different N-application
rates on grain yield, root growth and activity, uptake of
N and its use-efficiency, leaf chlorophyll content, leaf Nconcentration, and photosynthetic rate in comparison
with standard management practices for transplanted
flooded rice (TFR).
Results Overall, grain yield with SRI was 49 % higher
than with TFR, with yield enhanced at every N application dose. N-uptake, use-efficiency, and partial factor productivity from applied N were significantly
higher in SRI than TFR. Higher leaf nitrogen and
chlorophyll contents during the ripening-stage in SRI
plants reflected delayed leaf-senescence, extension of
photosynthetic processes, and improved root-shoot
activities contributing to increased grain yield.
Conclusions Rice grown under SRI management used
N fertilizer more efficiently due to profuse root development and improved physiological performance
resulting in enhanced grain yield compared to traditional flooded rice.Not Availabl
Not Available
Not AvailableIncreasing scarcity of irrigation water calls for enhancing water use efficiency (WUE) of crops, and improved
planting method is a potential option. Field experiments were conducted for 3 years to evaluate effects of three
planting methods of groundnut viz. flat-bed, ridge and furrow and paired-row at four irrigation regimes viz. 1, 2,
3 and 4 irrigations. Ridge and furrow, and paired-row methods resulted in an increase in pod yield by 13 and
17% and irrigation water saving by 26.7 and 41.7%, respectively compared with flat-bed method. Although
highest yield level was similar in ridge and furrow and paired-row methods with four irrigations, irrigation water
was 28.4% less in the latter than the former. In the three irrigation x paired-row method, pod yield reduced by
only 3.8%, whereas water saving was 26.9% compared to the four irrigations x paired-row method. Better root
dry weight, greater intercepted photosynthetically active radiation, chlorophyll fluorescence (Fv/Fm and ФPS II)
and rate of leaf photosynthesis contributed to higher yield and nutrient uptake under paired-row at higher
irrigation regime than traditional flat-bed method. Although evapotranspiration (ET) increased with higher irrigation
regimes; ridge and furrow and paired-row method decreased ET by 13 and 21%, and increased crop
WUE by 32.6 and 48%, respectively over flat-bed. The pod yield (Y)-ET functions were found linear; it has been
revealed that the crop will achieve maximum pod yield (2109 kg ha−1) with 359mm ET under paired-row
planting. Computed elasticity of water production and crop yield response factor could well be used for making
irrigation decisions. This field study confirmed that paired-row planting and furrow irrigation had increased pod
yield, saved water and enhanced WUE of groundnut under hot sub-humid conditionsNot Availabl
Not Available
Not AvailableRice is the staple food for half of the world’s population, and rice farming is a livelihood for millions of
farmers in Asia. In India, it provides an individual
with 32% of the total calorie and 24% of the total protein daily. This crop is mostly grown in puddled soil
by transplanting, and flood irrigation is practised by
farmers. Water or irrigation input to transplanted
rice typically ranges from 1000 to 2000 mm depending
upon the growing season, climatic condition, soil type
and hydrological conditions. Facing water scarcity
and climate change, reducing water requirement of
this crop is a challenge. Out of 42.75 million hectare
(m ha) rice area, only 25.12 m ha is under irrigation.
Regarding water resources, depletion of groundwater
is alarming in the north Indian states. On the other
hand, it is under-utilized in eastern India. Microirrigation, i.e. sprinkler and drip methods have been
used with the aim of minimizing water use and
enhancing water use efficiency of rice. In addition,
evidence-based scientific understandings on microirrigation for rice have been elucidated in this article.
The potential of drip or sprinkler irrigation to rice on
water saving as well as scientific insight and critical
appraisal have been expounded on reasons of yield
reduction. This comprehensive treatise would facilitate
the formulation of strategies or policies on efficient
management of water or irrigation for rice cultivation.Not Availabl
Not Available
Not AvailableABSTRACT
Achieving higher productivity in irrigated rice production is becoming ever-more important. A modified ricecultivation method, the System of Rice Intensification (SRI), recommends keeping rice fields moist but unflooded
during the crop’s vegetative stage, usually with alternate-wetting-and-drying (AWD), then maintaining shallow
flooding during the post-vegetative stage of crop growth. However, no evidence is available on how flooding
paddy fields continuously vs. alternately during the post-vegetative stage under SRI might influence the crops’
physiology, root growth, grain yield, and water productivity.
Field experiments were conducted to investigate the impacts of two alternative crop management systems,
namely, SRI and conventional management practice (CMP) under different water management treatments
during the vegetative stage [continuous flooding (CF) vs. AWD] and then during post-vegetative stage: CF vs.
AWD @ 1-DAD (days after disappearance of ponded water), 3-DAD or 5-DAD.
SRI practices, compared to CMP methods, significantly improved plants’ root growth and xylem exudation
rate, leaf area index and light interception by the crop canopy, plus photosynthesis rate at the grain-filling stage,
resulting in higher grain yield. Overall, this modified method of rice crop management produced 58% higher
grain yield with 16% less water. Across all water management treatments, significantly more grain was produced
per unit of water applied with SRI management (6.3 kg ha-mm−1
) compared to CMP (3.3 kg grain ha-mm−1
).
The highest grain yield with SRI (6.2 t ha−1
), and the greatest water productivity (6.7 kg ha-mm−1
) were obtained with SRI and 3-DAD post-vegetative irrigation. With CMP, highest grain yield (4.1 t ha−1
) and water
productivity (3.5 kg ha-mm−1
) were with 1-DAD irrigation.
Differences measured in plants’ response to modified management practices and alternative irrigation schedules indicated how phenotypic and physiological performances can be improved for a given genotype.
Combining changes in crop and water management can improve water productivity as well as grain yield.Not Availabl
Not Available
Not AvailableAttempts were made to study the effect of stocking density and water saving approach on water and sediment quality, growth and production performance of shrimp (Litopenaeus vannamei). The experiment was carried outwith three stocking density of post-larvae i.e. 400,000 per ha (T1), 500,000 per ha (T2) and 600,000 per ha (T3).Water exchange was carried out depending on water quality parameters. Water quality suitability index (WQSI) was lower at higher stocking density as was evident in T3 followed by T2 and T1. A very good WQSI (7.5–9.0) was recorded up to 13th, 12th and 9th week of culture in T1,T2 and T3, respectively; which was ascribed to stocking density, smaller shrimp size and less initial feed input. In L. vannamei culture, optimum stocking density of 50 post-larvae per m2 (T2) led to total water use of 3.42 × 104 m3 and water exchange of 0.80 × 104 m3. It was perceived as a way to improve shrimp productivity (10.31 t/ha 120/d), consumptive water use index (1.93 m3/kg biomass), total water footprint (1426 m3/t biomass), net consumptive water productivity (USD1.13/m3) and ratio of output value to the cost of cultivation (1.99). Further, farming systems with low to moderate water exchange as in T2, helped maintain water quality suitable for the shrimp growth, improved water use efficiency (518 g biomass/m3 water), minimized quantity of sediment load (41.7 m3/t biomass) and effluent outputs (0.8 × 104 m3). The knowledge derived from this study could provide the basis to optimize pond rearing efforts in shrimp culture and the water management strategies can be tailored to minimize production costs.Statement of relevance: This paper presents findings and analysis, from a methodologically rigorous investigation and provides insight regarding density-dependent optimum water use, its effect on pond water quality, sedimentation rate, growth performance, water productivity and water footprint. The knowledge derived from this study may be a basis to optimize pond rearing efforts in shrimp culture and the water management strategies can be tailored to prevent wasteful use of water and enhance water use efficiency and water productivity.Not Availabl
Not Available
Not AvailableConserving soil moisture in the rainfed region is a challenging task as it plays a significant role in crop
productivity and livelihood security of rainfed farmers. The soil moisture conservation practices (MCPs) coupled with the addition of root augmenting nutrition are crucial for sustaining crop yields and maintaining soil phosphorus (P) in a rainfed Vertisol of Central India. Thus, a study was conducted to evaluate the long-term effect of MCPs and P application in maize–chickpea in a Vertisol. A five-year study showed that the MCPs integrated with P nutrition significantly helped in growing chickpea (Cicer arietinum) without irrigation or with limited irrigation. Under the normal rainfall conditions such as normal onset time, distribution and cessation time during the experimentation, the MCPs proved useful in obtaining chickpea yields in the range of 776 to 933 kg ha-1. The best MCP was the practice of late intercultural operations ? Gliricidia cover in the inter-row spaces of standing maize (@ 5 t ha-1 fresh weight basis) ? maize stover application (after sowing up to germination), which recorded higher chickpea grain yield (932 kg ha-1) on account of higher moisture content in the soil and reduced stress in the plants. Another comparable treatment was Gliricidia cover ? one pre-sowing irrigation of 6 cm for chickpea, which recorded 933 kg ha-1 of chickpea yield. Both the treatments recorded significantly higher yields than the under control (637 kg ha-1). We also found that the application of Gliricidia cover on the soil surface coupled with either pre-sowing irrigation and/or late intercultural operations had beneficial effect on soil physical conditions increasing soil moisture which in turn affected the crop growth. Under normal monsoon years, the best treatments (MCP4 and MCP5) recorded around 46% higher chickpea yield as compared to the control. It is concluded that these soil MCPs are very useful in rainfed areas for sustaining crop yield.
Keyword Soil management , Moisture consNot Availabl
Controlling T-Cell Activation with Synthetic Dendritic Cells Using the Multivalency Effect
Contains fulltext :
174408.pdf (publisher's version ) (Open Access)Artificial antigen-presenting cells (aAPCs) have recently gained a lot of attention. They efficiently activate T cells and serve as powerful replacements for dendritic cells in cancer immunotherapy. Focusing on a specific class of polymer-based aAPCs, so-called synthetic dendritic cells (sDCs), we have investigated the importance of multivalent binding on T-cell activation. Using antibody-functionalized sDCs, we have tested the influence of polymer length and antibody density. Increasing the multivalent character of the antibody-functionalized polymer lowered the effective concentration required for T-cell activation. This was evidenced for both early and late stages of activation. The most important effect observed was the significantly prolonged activation of the stimulated T cells, indicating that multivalent sDCs sustain T-cell signaling. Our results highlight the importance of multivalency for the design of aAPCs and will ultimately allow for better mimics of natural dendritic cells that can be used as vaccines in cancer treatment
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