CONSERVING OF THE RESOURCES
Relation between the irrigation rate and the yield of long-fruit cucumbers grown in the Sofia field
- 1 Institute of Soil Science, Agro-Technology and Plant Protection “Nikola Pushkarov", Sofia, Bulgaria
In order to establish the parameters of the dependence of irrigation norm – yields of long – fruit cucumbers a field experiment was carried out in the period 2001-2004, on a chromic luvisols soil (chromic forest soil) . Different irrigation regimes have been tested – from full satisfaction of the culture’s daily needs of water, to irrigation with irrigation norms reduced with 20% and 40% .The soil moisture content in the layer 0-0.5 m is used as a criterion for determining the time for making a polish. Under optimal variant (variant 2), the same is maintained with over 85% of WHC.
It has been found that reducing the irrigation rate leads to a corresponding reduction in yield but it is disproportionate. In all cases, the reduction in yield is less than the decrease in the irrigation rate.Parameters of “water-yield” dependency are determined by the two-step formula of Davidov, which approximates the test points by S-curve at a correlation coefficient R = 0,999. The results show the variation of yields depending on the reduction of the irrigation rate. In the calculations obtained, the values of the gradation indicators n = 2,25 and m = 1,48 can be used to optimize the irrigation regimens of long-fruit cucumbers.
- Varlev I., P. Petkov, K. Karaivanov, 2012. Optimization of the duration of one irrigation. "Agricultural Machinery" magazine, No 3. S, р.7
- Varlev I. Et. al. 2013. Economic optimal irrigation rate for water users. "Agricultural Machinery" magazine No 1. S, р.9
- Varlev I. 1981. Study of the "yield-water" dependence and its use in irrigation. International Agricultural Magazine No 3. С, р.26
- Davidov D. 1982. The connection "yield-water". Sp. "Hydrotechnics and meliorations" №7. S, p.8
- Petkov P., I. Varlev, K. Karaivanov, 2013. Determination of economically optimal dimensioning norm and the economic effect of drip irrigation of vegetables.. "Waterworks" № 5/6. s, p 33
- Davidov,D., 1994. On the Grounds of the Relationship “Yield–Water”. 17th European Regional Conference on Irrigation and Drenage ICID–CIID, Varna, Bulgaria, vol. 1, 251-253 (Bg)
- Frecman, B., Carzoli, 1980, Localized Irrigation FAO, Irrigation and Drainage pp 36