Person: Humphreys, E.
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Humphreys
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E.
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Humphreys, E.
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0000-0002-9875-8885 6 results
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- Guidelines for dry seeded aman rice (DSR) in Bangladesh(IRRI, 2014) Gathala, M.K.; Sudhir-Yadav; Mazid, M.A.; Humphreys, E.; Ahmed, S.; Krupnik, T.J.; Rashid, M.H.; Chauhan, B.S.; Kumar, V.; Russell, T.; Saleque, M.A.; Kamboj, B.R.; Jat, M.L.; Malik, R.; Tiwari, T.P.; Mondal, M.; Rahmand, M.; Saha, A.; Hossain, K.; Saiful Islam; Mcdonald, A.Dry seeded rice (DSR) is becoming an attractive option for farmers as it has a much lower labor requirement than manually transplanted rice. Labor for transplanting rice has become scarce and costly because laborers are shifting from agriculture to industry, public works and services, and migrating abroad. DSR can be readily adopted by small farmers as well as large farmers, provided that the required machinery is locally available (e.g., through custom hire from agricultural service providers). Best practice involves using a 2- or 4-wheel tractor-drawn drill to seed in rows into nontilled or dry tilled soil, as for wheat. Because the soil is not puddled, DSR also has a lower water requirement for crop establishment, and may require less frequent irrigation than puddled transplanted rice grown with alternate wetting and drying water management during dry spells. Where arsenic contaminated groundwater is used, less irrigation means less arsenic brought to the soil surface. Furthermore, accumulation of arsenic in the grain and straw is much less if the soil is allowed to dry between irrigations to let air (oxygen) into the soil (“aerobic” conditions) than in continuously flooded rice.
Publication - Evaluation of the effects of mulch on optimum sowing date and irrigation management of zero till wheat in central Punjab, India using APSIM(Elsevier, 2016) Singh, B.; Humphreys, E.; Gaydon, D.; Eberbach, P.L.Machinery for sowing wheat directly into rice residues has become more common in the rice-wheatsystems of the north-west Indo-Gangetic Plains of South Asia, with increasing numbers of farmers nowpotentially able to access the benefits of residue retention. However, surface residue retention affectssoil water and temperature dynamics, thus the optimum sowing date and irrigation management for amulched crop may vary from those of a traditional non-mulched crop. Furthermore, the effects of sowingdate and irrigation management are likely to vary with soil type and seasonal conditions. Therefore,a simulation study was conducted using the APSIM model and 40 years of weather data to evaluatethe effects of mulch, sowing date and irrigation management and their interactions on wheat grain yield,irrigation requirement (I) and water productivity with respect to irrigation (WPI) and evapotranspiration(WPET). The results suggest that the optimum wheat sowing date in central Punjab depends on both soiltype and the presence or absence of mulch. On the sandy loam, with irrigation scheduled at 50% soilwater deficit (SWD), the optimum sowing date was late October to early November for maximising yield,WPIand WPET. On the clay loam, the optimum date was about one week later. The effect of mulch onyield varied with seasonal conditions and sowing date. With irrigation at 50% SWD, mulching of wheatsown at the optimum time increased average yield by up to 0.5 t ha−1. The beneficial effect of mulch onyield increased to averages of 1.2–1.3 t ha−1as sowing was advanced to 15 October. With irrigation at 50%SWD and 7 November sowing, mulch reduced the number of irrigations by one in almost 50% of years,a reduction of about 50 mm on the sandy loam and 60 mm on the clay loam. The reduction in irrigationamount was mainly due to reduced soil evaporation. Mulch reduced irrigation requirement by more assowing was delayed, more so on the sandy loam than the clay loam soil. There was little effect of mulchon irrigation requirement for late October sowings.There were large trade-offs between irrigation input, yield, WPETand WPIon the sandy loam with regardto the optimum irrigation schedule. Maximum yield occurred with very frequent irrigation (10–20% SWD)which also had the greatest irrigation input, while WPIwas highest with least frequent irrigation (70%SWD), and WPETwas highest with irrigation at 40–50% SWD. This was the case with and without mulch.On the clay loam, the trade-offs were not so pronounced, as maximum yield was reached with irrigationat 50% SWD, with and without mulch. However, both WPETand WPIwere maximum and irrigation inputleast at the lowest irrigation frequency (70% SWD). On both soils, maximum yield, WPETand WPIwerehigher with mulch, while irrigation input was slightly lower, but mulch had very little effect on theirrigation thresholds at which each parameter was maximised.
Publication - Guidelines for Dry Seeded Rice (DSR): in the Cauvery Delta Zone, Tamil Nadu, India / Sudhir Yadav and others(CSISA, 2014) Sudhir-Yadav; Ganeshamoorthy, R.; Humphreys, E.; Rajendran, R.; Ravi, V.; Mussgnug, F.; Kumar, V.; Chauhan, B.S.; Ramesh, T.; Kamboj, B.R.; Gathala, M.K.; Malik, R.; Jat, M.L.; Mcdonald, A.Dry seeded rice (DSR) is becoming an attractive option for farmers in the Cauvery Delta Zone (CDZ) due to the elimination of the labor requirement for nursery preparation and maintenance, pulling out and transport of seedlings, and transplanting. Because the soil is not puddled, DSR also has a lower water requirement for crop establishment. Furthermore, the total crop cycle is shorter by 10−15 days because of the absence of transplanting shock. These features of DSR are of major importance for the Cauvery Delta (see below) because of the increasing scarcity of water for irrigation in the area. DSR can be readily adopted by small farmers as well as large farmers, provided that the required machinery is locally available (e.g., through custom hire). Best practice involves using a 2- or 4-wheel tractordrawn drill to seed in rows in dry or slightly moist soil.
Publication - Guidelines for Dry Seeded Rice (DSR): in the Terai and Mid Hills of Nepal(CSISA, 1999) Krishna Prasad Devkota; Sudhir-Yadav; Ranjit, J.D; Sherchan, D.P.; Regmi, A.P.; Akhtar, T.; Humphreys, E.; Chauhan, B.S.Dry seeded rice (DSR) is becoming an attractive option for farmers as it has a much lower labor requirement and establishment cost than manually transplanted rice. Labor for transplanting rice has become scarce and costly because laborers are shifting from agriculture to industry, public works, and overseas employment. DSR can be readily adopted by small farmers as well as large farmers, provided that the required machinery is locally available (e.g., through custom hire). Best practice involves using a 2- or 4-wheel tractor-drawn drill to seed in rows in nontilled or dry tilled soil, as for wheat. Because the soil is not puddled, DSR also has a lower water requirement for crop establishment.
Publication - Guidelines for dry seeded rice (DSR) in the Eastern gangetic plains of India(IRRI, 2013) Yadav, S.; Malik, R.; Humphreys, E.; Kumar, V.; Singh, S.S.; Bhagirath, S.; Kamboj, B.R.; Gathala, M.K.; Jat, M.L.; Mcdonald, A.; Laik, R.Dry seeded rice (DSR) is becoming an attractive option for farmers as it has a much lower labor requirement than manually transplanted rice. Labor for transplanting rice has become scarce and costly because laborers are shifting from agriculture to industry, public works, and services. This document is meant to be a guideline for the production technology of DSR in Bihar and Eastern Uttar Pradesh (Eastern Gangetic Plains) India.
Publication - Water saving in rice-wheat systems(Taylor & Francis, 2005) Humphreys, E.; Meisner, C.A.; Gupta, R.K.; Timsina, J.; Beecher, H.G.; Tang Y.L.; Yadvinder-Singh; Gill, M.A.; Masih, I.; Zheng Jia Guo; Thompson, J.A.Water shortage is a major constraint to sustaining and increasing the productivity of rice-wheat systems. Saving water can be elusive in that reducing seepage, percolation and runoff losses from fields does not necessarily save water if it can be recaptured at some other temporal or spatial scale, for example by groundwater pumping. Many technologies appear to save substantial amounts of water through reducing irrigation water requirement, but whether these are true water savings is uncertain as components of the water balance have not been quantified. Such technologies include laser levelling, direct drilling, raised beds, non-ponded rice culture and irrigation scheduling. It is questionable whether puddling saves water. Reducing non-beneficial evaporation losses is a true water saving, and optimal planting time of rice to avoid the period of highest evaporative demand and changing to non-ponded rice culture can save significant amounts of water. However, moving away from puddled, ponded to more aerobic rice culture sometimes brings new production problems. Furthermore, farmers faced with unreliable water supplies need to store water on their fields as insurance, and puddling assists retention of water during the rice crop. Rehabilitation and improvement of canal and power systems in Asia, funded by charging according to use, are required to facilitate adoption of many water saving technologies. Australian farmers pay fixed plus volumetric charges for water to cover the cost of infrastructure and operation of irrigation systems, which are continuously being improved to provide water on demand and minimise losses. They are able to plan their plantings based on knowledge of the likely amount of irrigation water available each season and crop water use requirement, and thus avoid wasting water and financial loss by overplanting and crop failure. Such approaches have the potential to increase production and water productivity in Asia, however the challenge would be to apply them in an equitable way that benefits many millions of subsistence farmers.
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