DETERMINATION OF WATER-EFFICIENCY RELATIONSHIPS AND SILAGE QUALITY CHARACTERISTICS OF THE MAIZE SPECIES FOR SILAGE(ZEA MAYS L.)THE FIRST PRODUCT GROWN UNDER SEMI-ARID CLIMATE CONDITIONS

Abstract

In this study, a field study was carried out to determine the effect of different irrigation water amounts on dry matter efficiency and silage quality features of species of corn for silage P32K61, P31Y43, P30B74 and the relationship of water and dry matter, as well as the threshold value of the dry substance to be used in silage quality estimation by leveraging such relationship. The study was planned as three repeats in a trial pattern of divided parcels in randomized blocks. Irrigation program was established by reapplication of 100% (I100), 70% (I70), 35% (I35) of the water consumed every 7 days with the drip irrigation method. Thus, the irrigation consists of 1 full and 2 different deficit irrigation. In the study, irrigation water amount applied to I100,I70 and I35 of types P32K61, P31Y43 and P30B74 was 637-653-666; 491-495-509; 342-363-371 mm, respectively, seasonal plant water consumption values were 705-714-738; 559-554-583mm, dry matter efficiency values ranged from 24.38-24.29- 32.36, 23.26-23.33-25.5, and 12.8-14.46-14.13 t ha- 1 . Linear relations were determined between dry matter (DM) efficiency of the species and irrigation water (I) as DM=20.57I+6369(r2=0.997**), DM=30.95I+4340(r2=0.999**),Y=36.14I+5826 (r2=0.998**);and between dry matter-plant water consumption (ETa) values as Y=26.02ETa+832.1(r2=0.969**),Y=36.55ETa- 22.83 (r2=0.995**), Y=42.75ETa-1949 (r2=0.997**). The highest and lowest protein amounts by irrigation were 8.67% in the interaction of I100 irrigation and P32K61 species and 6.14% in the interaction of I35 irrigation and P31Y43 species, respectively; digestible dry matter ratio was 70% in the interaction of I100 irrigation and P30B74 species and 60% the interaction of I35 irrigation and P31Y43,respectively. No statistically significant relation between the ADF (Acid Detergent Fiber) and NDF (Neutral Detergent Fiber) values was found. The highest water consumption efficiency was 4.38 kg/da-mm in I100 irrigation and 3.37 kg/damm in I35 irrigation. In addition, thecorrelation coefficient between ET, dry matter and protein amount was r 2 :0.81** and r 2 :0.80**, and a statistically significant positive relationship was observed (p<0.01) between ETa, dry matter and protein amount. As a result of statistical and economic analyses, threshold dry matter efficiency value on which the silage quality starts to drop was determined at 25.5 t ha-1 in I70 irrigation.