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[en] Comparison of furrow and trickle methods of irrigation to know their relative efficiency with respect to water applied and fertilizer used on tomatoes, cauliflower and lettuce as test crops using canal water, showed a significant saving of about 44 and 41 per cent respectively for irrigation water and fertilizer applied with trickle as compared to furrow irrigation. Trickle irrigated crops also showed a better response as regards the rate of survival, crop growth and time of maturity
[en] Results of a field experiment on the effects of two irrigation treatments and rain-fed on yield and crop water use of groundnut is presented in this paper. Yield of groundnut (3.1 t. ha-' and 3.2 t. ha-' respectively) show good response to both irrigation treatments when earlier flowering stage coincide with a dry period. Data on changes in soil water content with time, measured by a neutron moisture gauge was used to estimate crop water use/crop evapotranspiration using a water balance approach in the presence of zero flux plane. The low water use of groundnut (64.5 mm) grown in the rain-fed plot when compared to both the irrigated plots (124.5 mm and 152 mm respectively) during a dry period resulted in a low yield of 1.9 t. ha-'. In the rain-fed plot, from early flowering to start of pod setting stage, the soil at 20 cm depth constantly dry, as indicated by a continuously decreasing value of the hydraulic head value to < -7OkPa. With the yield response factor ky for flowering stage being 0.74, the decrease in groundnut yield due to water deficit flowering stage is relatively large
[en] There is an emerging understanding toward the importance of land-atmosphere interactions in the monsoon system, but the effects of specific land and water management practices remain unclear. In this work, using regional process-based experiments, we demonstrate that monsoon precipitation is sensitive to the choice of irrigation practices in South Asia. Experiments with realistic representation of unmanaged irrigation and paddy cultivation over north-northwest India exhibit an increase in the late season terrestrial monsoon precipitation and intensification of widespread extreme events over Central India, consistent with changes in observations. Such precipitation changes exhibit substantially different spatial patterns in experiments with a well-managed irrigation system, indicating that increase in unmanaged irrigation might be a factor driving the observed changes in the intraseasonal monsoon characteristics. Our findings stress the need for accurate representation of irrigation practices to improve the reliability of earth system modeling over South Asia.
[en] A lysimeter experiment was conducted to evaluate the impact of saline water irrigation at three levels namely, fresh water (0.3), 4 and 8 dS/m on salt accumulation and its effect on different soil types. The tested halophyte plants were Kallar grass and Atriplex (Salt bush). The tested soil types were sandy, calcareous and clayey soils. Irrigating the soil with saline water (either 4 or 8 dS/m) resulted in increasing salinity levels in soil profile with different orders of magnitude, depending on the soil type layer and the cultivated plant. Kallar grass seems limit the accumulation of salts in soil profile, compared to Atriplex at any tested soil. This may be attributed to its root effect on soil profile such as dispersed soil matrix and improved soil structure, which provide channels for solute movement through the profile under halophyte cultivation. Calculating the SAR average values for each irrigation treatment (18 values) showed significant increase in soil SAR values, especially under Kallar grass compared to Atriplex. The highest SAR values were observed in the case of clayey soil. However, the relevant SAR values under Atriplex cultivation were always lower. Values for SAR were always higher in the saline clayey > calcareous > sandy soils
[en] Hydrological droughts are a major risk for irrigated agriculture in many regions of the world. The aim of this article is to propose an insurance tool to help irrigators manage the risk of water scarcity in the framework of the Spanish Crop Insurance System (SCIS). Only the United States Insurance System provides this type of coverage, but has very restrictive conditions. To determine the type of insurance scheme that better fits with the SCIS and to the Spanish irrigated agriculture, an expert panel was held with the participation of all stakeholders involved in crop insurance. Following the expert panel conclusions, an hydrological drought index insurance (HDII) addressed to irrigation districts (ID) is proposed. It would compensate water deficits suffered in the whole ID. We detail the conditions that the ID should fulfill to be eligible for HDII. HDII is applied to the Bardenas Irrigation District V (ID-V) in Spain, and the hedging effectiveness of the instrument is analyzed comparing ID-V’s gross margins with and without the insurance contract. Results suggest that the proposed insurance scheme could provide an effective means of reducing farmers’ vulnerability to water shortages and there is no major impediment for it to be included as a new line in the SCIS. This type of insurance can be generalized to any ID fulfilling the conditions mentioned in this paper. (Author)
[en] Water deficit (WD) is becoming an alarming problem in many regions of the world. Jasmonic acid (JA) is considered an important intracellular plant growth regulator. The aim of the current research was to investigate the important role of JA in mitigating the negative effects of WD on plant growth. Sugar beet production systems of two locations in Chaharmahal-Bakhtiari province, Iran. A field trial was conducted to assess the foliar applications of JA (0, 5 µM and 10 µM) and WD (50%, 75%, 100% plant water requirements) effects on physiological yield components of sugar beet (Beta vulgaris L.) plants. WD significantly (p<0.05) increased catalase, ascorbate and peroxidase activities, and malondialdehyde, hydrogen peroxide and white sugar content (WSC); however, it caused a reduction in white sugar yield and root yield (RY). JA foliage applications further enhanced the enzymes activity in WD treated plants resulting in higher WSC, potassium concentrations, white sugar and final RY. Interestingly the effects of JA applications were more pronounced under severe WD (50%) compared to mild (75%) or well-watered plants (100%). JA (10 µM) foliage applications increased the RY and white sugar production by 21% and 24% under severe WD. JA can ameliorate the adverse effects of WD and increase the WD tolerance of sugar beet crop by upregulating the antioxidant enzyme activities to withstand adverse environmental conditions.