WATER AND FERTILIZER MANAGEMENT OF CANTALOUPE CROP UNDER DRIP IRRIGATION SYSTEM

Abstract

As fresh water resources become scarce, it is difficult to irrigate crops to meet their full demand. The Arabic region is considered one of the most vulnerable regions to climate change impacts, on account of its water scarcity, which is the highest in the Arab world. Improvements to irrigation management are proposed as a way of increasing agricultural production and reducing the demand for water. One way to achieve greater water use efficiency in irrigation is switching from the less efficient flood or furrow system to more efficient systems such as trickle irrigation (surface, subsurface) or to adopt irrigation strategies, such as deficit irrigation, in order to maximize crop yield and or minimize water losses. The deficit irrigation (DI) strategy, in which irrigation is reduced below the evapotranspiration demand of the crop throughout the growing season, may be acceptable in the Arab region now to cut down water use and energy costs. However, it may be worthwhile to start thinking about it now to lay a strategy for the long term considering the rapidly growing demand for the groundwater due to the tremendous increase in water use for crops.

The specific objectives of this study: 1-To study the effect of water and fertilization applied (as quantified by different irrigation and fertilization levels) for drip irrigation system on cantaloupe yields and quality . 2-To determine the optimum water use and water use efficiency for the cantaloupe crop. 3-To develop a fertilization crop productionfunction , develop of optimal management for applying water and fertilizers under drip irrigation system .

The experiment was carried out during season of 2014 at the Experimental Farm of Agriculture Faculty, Ain Shams University, Shalaqan village, Qalyubia Governorate, Egypt, that represents an alluvial soil conditions of Delta region,to study effect ofirrigation and fertilization requirements, using drip irrigation, three irrigation treatments (100%, 80% and 60% ETc) and two fertilization levels (100%N and 50%N) on yield , quality and water use efficiency of cantaloupe .

The results of this study are summarized as follows: 1-Cumulative irrigation water requirement of different irrigation treatments in the growing season were (963.24, 1284.41 and 1605.50 m3) for (60%, 80% and 100% ETc) respectively. 2-Moisture content increased near the emitter source and then decreased horizontally and vertically in all cases this may be due to the increase of the irrigation periods and converge of the distance between the emitters 3-Decrease of salt concentration below the emitter while incense away horizontally and vertically for all of the studied coefficients 4-Increasing the irrigation levels increases the weight, flesh thickness, length, diameter, number fruits per plant and total yield, and decreased firmness, TSS, total sugar, of cantaloupe fruit. 5-Increasing the nitrogen levels increased the weight, number of fruits per plant and total yield, and decreased firmness, TSS, total sugar, of cantaloupe fruit. 6-The effect of interaction (irrigation X fertilizer (N) ) on weight, flesh thickness, length, diameter, number of fruits per plant and total yield of cantaloupe fruits, showed that (100% Etc, 100%N) treatment exhibited the highest value in weight flesh thickness, length, diameter, number fruits per plant and total yield of fruit followed by (100% Etc, 50%N) treatment, then (80% Etc, 100%N) and (80% Etc, 50%N) treatments with gradual decreased in of fruit values, while, the lowest values were obtained with (60% Etc, 100%N) and (60%Etc, 50%N) treatments, respectively. 7- Effect of interaction (irrigation X fertilizer (N) ) on firmness, TSS, Total sugars of cantaloupe fruits, showed that (60% Etc, 50%N) treatment the highest value in firmness, TSS, total sugars of fruit followed by (60% Etc, 50%N) treatment had then (80% Etc, 50%N) and (80% Etc, 100%N) treatments ,while, the lowest values were obtained by (100% Etc,100%N) and (100%Etc,50%N) treatments, respectively. 8- The IWUE value ranged from 7.96 kg/ m3to 10.21 kg/ m3depending on the irrigation treatments. The highest IWUE value was 10.21 kg/ m3for (60% Etc and 100%N) treatment, while, the lowest IWUE value was 7.96 kg/m3for (100% Etc and 50%N) treatment. Generally, IWUE of the various irrigation levels tended to increased with (60% Etc)treatment. Then decreased with (80 %Etc) treatment. Then more decreased with (100% Etc) treatment. IWUE values decreased with increasing water level. 9-The NUE values ranged from 68.85( kg / kg-N)to 178.86 ( kg / kg-N) depending on the nitrogen treatments. The highest NUE value was178.86 ( kg / kg-N) for (100% Etc and 50%N) treatment, while, the lowest NUE value was 68.85( kg / kg-N)for (60% Etc and 100%N) treatment. Generally, NUE of the various nitrogen treatments tended to increased with (50%N)treatment, and decreased with (100% Etc.) treatment. NUE values decrease with increasing nitrogen level. 10-The capital total costs for irrigating cantaloupe increased from 401.22 to 668.7 LE/fed by increasing irrigation treatments from 60, 80 and 100% of Etc. on the other hand, the highest cost of production of one ton of cantaloupe yield was 52.33LE/ton under the treatment of 100%Etc and 50%N, while the lowest value of cost was 40.77 LE/ton under 60%ETc and 100%N.