Pan evaporation and sensor based approaches of irrigation scheduling for crop water requirement, growth and yield of okra

The results of this study revealed that the pan evaporation and sensor based irrigation scheduling along with fertigation scheduling significantly affected the plant height, fruit weight, fruit length, crop water requirement, crop yield and water use efficiency of okra crop. The pan evaporation and crop evapotranspiration (ETc) values significantly vary over different stages of okra crop. The maximum and minimum average daily pan evaporation was recorded 8.4 mm day-1 and 4.5 mm day-1 at mid stage and late stage of okra crop respectively while, the maximum average daily ETc was recorded 7 mm day-1 at mid stage of okra crop. A approach of irrigation scheduling with 100 per cent field capacity, based on soil moisture sensor under automated drip irrigation system along with 100 per cent RDF through fertigation in equal splits at 4 day intervalor 80 % per cent of volume of crop water requirement based on pan evaporation under automated drip irrigation along with 100 per cent RDF through fertigation in equal splits at 2 day interval, can be used for irrigating okra crop with significant water saving, crop yield and water use efficiency under limited availability of daily weather datain climatic condition of Udaipur district of Rajasthan.

Implication of Climate Change On Crop Water Requirement: A Regional Case Study in The Semi-Arid Region of Western Maharashtra, India

The hydrological cycle has been massively impacted by climate change and human activities. Thus it is of the highest concern to examine the effect of climate change on water management, especially at the regional level, to understand possible future shifts in water supply and water-related crises, and to provide support for regional water management. Fortunately, there arises a high degree of ambiguity in determining the effect of climate change on water requirements. In this paper, the Statistical DownScaling (SDSM) model is applied to simulate the potential impact of climate on crop water requirement (CWR) by downscaling ET0 in the region of Western Maharashtra, India for the future periods viz., 2030s, 2050s, and 2080s across three meteorological stations (Pune, Rahuri, and Solapur). Four crops i.e. cotton, soybean, onion, and sugarcane are selected during the analysis. The Penman-Monteith equation is used to calculate reference crop evapotranspiration (ET0), which further in conjunction with the crop coefficient (Kc) equation is used to calculate crop evapotranspiration (ETc) / CWR. The predictor variables are extracted from the NCEP reanalysis dataset for the period 1961-2000 and the HadCM3 under H3A2 and H3B2 scenarios for the period of 1961 – 2099. The results indicated by SDSM profound good applicability in downscaling due to satisfactory performance during calibration and validation for all three stations. The projected ET0 indicated an increase in mean annual ET0 as compared to the present condition during the 2030s, 2050s, and 2080s. The ET0 would increase for all months (in summer, winter, and pre-monsoon seasons) and decrease from June to September (monsoon season). The estimated future CWR show variation in the range for cotton (-0.97 to 2.48%), soybean (-2.09 to 1.63 %), onion (0.49 to 4.62 %), and sugarcane (0.05 to 2.86 %).

Assessment of crop water requirement of field pea (Pisum sativum L.) in foothills valley areas of Manipur, North East India

The purpose of this study was to assess the evapotranspiration in field pea (Pisum sativum L.) in foothills valley areas of Manipur using the Hargreaves-Samani equation to predict the plant water demand. The crop coefficient (Kc) values ranged between 0.45 and 1.28 during the crop growth stages of field pea for the five crop seasons (2013-18). The average five-year effective rainfall was estimated to be 59.0 mm, with standard deviation (SD±) ranging between 4.4 to 35.1 mm. The average crop water requirement for field pea was estimated to be 221.0 mm and the average water demand for different crop growth stages of field pea was estimated to be 20.0 mm (initial stage), 52.0 mm (development stage), 100.0 mm (mid-season) and 49.0 mm (late season). Thus, the information generated may help in effective management of crop water requirements for sustainable crop production including field pea in the region.

DESIGN, CONSTRUCTION AND EVALUATION OF RUNOFF WATER HARVESTING POND FOR SMALLHOLDER FARMING

Rainfall shortage and variability constrain crop production of smallholder farmers in Ethiopia is the main problem. For this supplementary irrigation by run off harvesting is strategic pathway to reduce poverty in rural drought prone areas for enhancing agricultural productivity and boosting farm income. For this, this study is conducted to Design, construction and evaluation of runoff water harvesting Pond for supplementary irrigation to addressing inherent crop failures under the rain fed agriculture due to mainly erratic rainfall. For this design climatic and soil data were input to determine seasonal crop water requirement (CWR) of onion and evaporation loss of water from water surface. Then the performances of water harvested verses area irrigate were evaluated. To make this study more economical the water harvester capacity decreed by two fold and water harvesting made at two times. Seasonal volume crop water requirement (CWR) of onion for farm area 2500 m2 and evaporation loss of water from water surface of 121 m2 and total volume of seasonal water need were 382.05,53.38 and 435.43 m3 respectively. The geo-membrane laminated water harvester that has capacity of 223 m3 was designed and constructed. From on field performance shows, this volume of water harvested twice can irrigate 0.25ha by supplementary irrigation using water saving irrigation technology (treadle pump) by over showering and was produced 4.2 tone/ha. The investment, operation and production costs were 63116, 1125 and 6675 ETH birr respectively. The total cost was 70,916 birr and The growth return of 0.25ha was 15,750 birr/year (1050kg*15 birr/kg). This show the farmer can return 22.21% of their investment cost. So it is recommended to the government and non-government to initiate the farmers at lower stream of the catchment to harvest run off water and use for supplementary irrigation to increase their income.

Climate Change Effect on Irrigation Water Requirement of Wheat and Maize in Northern Part of Bangladesh

Bangladesh is one of the most vulnerable countries for climate change in agricultural water management. A research had been done to assess climate change effects on irrigation water use of wheat and maize in the northern part of Bangladesh. The twenty nine years of data (1990-2018) were analyzed with Mann-Kendall test as well as Sen’s slope for climate change impact and the responsible weather parameters due to climate change were identified with correlation coefficients. The crop water requirement of wheat in Bogura and Rangpur was declining at the rate of 3.3mm and 2.3mm per decade respectively. Net irrigation water requirement of wheat at both Bogura and Rangpur was inclining at the rate of 1mm and 10mm per decade respectively because the effective rainfall of these regions was decreasing at 5mm and 11mm per decade respectively. The crop water requirement of maize for similar districts was increasing at the rate of 3.2mm and 2.5mm per decade respectively although net irrigation water requirement had statistically non-significance for climate change effect. The weather parameter, which was mainly responsible for climatic change in irrigation water requirement, was increasing temperature. Therefore, wheat cultivation might be coped with climate change in the northern part of Bangladesh rather than maize on the basis of irrigation and water management.