Your search found 4 records
1 Dasgupta, P.; Das, B. S.; Sen, S. K. 2015. Soil water potential and recoverable water stress in drought tolerant and susceptible rice varieties. Agricultural Water Management, 152:110-118. [doi: https://doi.org/10.1016/j.agwat.2014.12.013]
Water stress ; Soil water potential ; Drought tolerance ; Lowland ; Rice ; Plant growth ; Plant developmental stages ; Soil water content ; Crop yield ; Physiological response ; Models / India / Kharagpur
(Location: IWMI HQ Call no: e-copy only Record No: H047497)
(0.73 MB)
We conducted a two-year field experiment to determine if water stress could be exploited to recover yield in one drought resistant (Vandana) and three susceptible (IR36, IR72 and Swarna) rice varieties. Stress was induced in active tillering, flowering and grain filling stages by suspending irrigation until the soil became sufficiently dry and plants began to show stress symptoms when irrigation was resumed, such that plants could recover from stress. We observed that terminal soil water potential (SWP) as low as -110 kPa in the active tillering stage was less detrimental to relative water content, proline content, and electrolyte leakage. A 27% rise in the level of stress led to ~8%, 44% and 21% increase in yield in IR36, Vandana and Swarna. The possible causes are 23%, 39% and 10% increase in the corresponding root biomass ofthe varieties, resulting in higher water uptake in the vegetative stage treatment plots. This was further supported by high correlations between yield and terminal SWP in this treatment. Critical limits of SWP may be identified to exploit the potential of rice varieties to sustain or improve yield under water stress. Results also suggest an opportunity to design a water saving strategy in lowland rice production.
2 Adimassu, Zenebe; Mul, Marloes; Owusu, Afua; Barron, Jennie; Kadyampakeni, Davie; Cofie, Olufunke O. 2016. Smallholder irrigation productivity for sustainable intensification: water balances for high value crops in northern Ghana. Ibadan, Nigeria: International Institute of Tropical Agriculture (IITA). 35p.
Smallholders ; Irrigation systems ; Water productivity ; Sustainability ; Intensification ; Water balance ; Estimation ; Rain ; Dry season ; Dry spells ; Rainfed farming ; Water management ; Crops ; Plant developmental stages ; Maize ; Vegetables ; Yield response functions ; Soil profiles ; Soil types ; Models / Ghana / Navrongo
(Location: IWMI HQ Call no: e-copy only Record No: H049041)
https://cgspace.cgiar.org/bitstream/handle/10568/83313/AR_WA_water_balance_dec2016.pdf?sequence=1&isAllowed=y
https://vlibrary.iwmi.org/pdf/H049041.pdf
https://vlibrary.iwmi.org/pdf/H049041.pdf
(1.63 MB) (1.63 MB)
3 Mwinuka, P. R.; Mbilinyi, B. P.; Mbungu, W. B.; Mourice, S. K.; Mahoo, H. F.; Schmitter, Petra. 2021. The feasibility of hand-held thermal and UAV-based multispectral imaging for canopy water status assessment and yield prediction of irrigated African eggplant (Solanum aethopicum L). Agricultural Water Management, 245:106584. [doi: https://doi.org/10.1016/j.agwat.2020.106584]
Water stress ; Eggplants ; Canopy ; Water requirements ; Crop yield ; Forecasting ; Infrared imagery ; Multispectral imagery ; Unmanned aerial vehicles ; Remote sensing ; Irrigated farming ; Irrigation water ; Performance evaluation ; Moisture content ; Vegetation index ; Plant developmental stages ; Temperature / Africa / United Republic of Tanzania / Rudewa Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050054)
https://www.sciencedirect.com/science/article/pii/S0378377420321314/pdfft?md5=25877087dd8e72a2377978976c8abc33&pid=1-s2.0-S0378377420321314-main.pdf
https://vlibrary.iwmi.org/pdf/H050054.pdf
https://vlibrary.iwmi.org/pdf/H050054.pdf
(6.03 MB) (6.03 MB)
This study was conducted to evaluate the feasibility of a mobile phone-based thermal and UAV-based multispectral imaging to assess the irrigation performance of African eggplant. The study used a randomized block design (RBD) with sub-plots being irrigated at 100% (I100), 80% (I80) and 60% (I60) of the calculated crop water requirements using drip. The leaf moisture content was monitored at different soil moisture conditions at early, vegetative and full vegetative stages. The results showed that, the crop water stress index (CWSI) derived from the mobile phone-based thermal images is sensitive to leaf moisture content (LMC) in I80 and I60 at all vegetative stages. The UAV-derived Normalized Difference Vegetation Index (NDVI) and Optimized Soil Adjusted Vegetation Index (OSAVI) correlated with LMC at the vegetative and full vegetative stages for all three irrigation treatments. In cases where eggplant is irrigated under normal conditions, the use of NDVI or OSAVI at full vegetative stages will be able to predict eggplant yields. In cases where, eggplant is grown under deficit irrigation, CWSI can be used at vegetative or full vegetative stages next to NDVI or OSAVI depending on available resources.
4 Masanganise, J.; Kunz, R.; Clulow, A. D.; Mabhaudhi, T.; Savage, M. J. 2022. Evapotranspiration estimates of soybean using surface renewal: comparison with crop coefficient approach. Physics and Chemistry of the Earth, 128:103244. (Online first) [doi: https://doi.org/10.1016/j.pce.2022.103244]
Evapotranspiration ; Estimation ; Soybeans ; Energy balance ; Sensible heat ; Latent heat ; Micrometeorology ; Crops ; Plant developmental stages ; Soil water content ; Weather data ; Air temperature / South Africa / KwaZulu-Natal
(Location: IWMI HQ Call no: e-copy only Record No: H051442)
(0.88 MB)
Evapotranspiration (ET) is widely considered the main consumptive water use in agricultural production and its accurate determination enables crop producers to make informed decisions. Field experiments were conducted in KwaZulu-Natal, South Africa to estimate soybean ET from sensible and latent heat flux obtained using the surface renewal (SR) method. Two versions of the SR method (SR2) were used. One version combines SR analysis with Monin-Obukhov similarity theory (MOST), hereinafter referred to as SRMOST. The other is a combination of SR analysis and dissipation theory (DT) referred to as SRDT. The ET estimated using SRMOST and SRDT (ETSRMOST and ETSRDT respectively) were compared to the ET obtained using the standard crop coefficient (Kc) approach (ETKc). During flowering, pod formation and seed filling, both SRMOST and SRDT methods slightly overestimated ET obtained using Kc approach with an average normalised root mean square error (NRMSE) of 23.4% and an average normalised mean absolute error (NMAE) of 10.1% for SRMOST and 21.7 and 9.4% for SRDT respectively. During senescence and at maturity, SRMOST and SRDT slightly underestimated ET compared to Kc approach. The average statistical measures for SRMOST were NRMSE = 21.0% and NMAE = 9.2%. Correspondingly, the statistics for SRDT were 17.5 and 7.1% respectively. Both SR2 methods estimated the minimum ET more accurately compared to the maximum. The SRDT method was more in agreement with Kc approach. Surface renewal is robust, less expensive than other micrometeorological techniques and a reliable method for deriving evapotranspiration of soybean when crop coefficients are problematic.
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