Effect of fertilization on the yield and fruit quality of perennial plantations under drip irrigation

Abstract

According to the results of previous studies it was specified that the soils of the research areas in south of Ukraine are not provided with the optimal content of nutrients for normal growth and development of fruit crops. As a result of that, a long-term field experiment was set up, which aimed at increasing soil fertility, yield and fruit quality of intensive plantations of peach and apple trees under drip irrigation as well as at improving soil management principles. The field experiment was set up in 2009 on the perennial plantations in Kherson and Mykolaiv regions on the soils with different properties using the water of different quality when applying traditional cultivation technology in the south of Ukraine. It was observed the positive effect on the yield of perennial plants when applying the following fertilizer systems: organic-mineral ("Rost-concentrate"), mineral (N120P30-90K75-120), and organic ("Gumoplant") when irrigating with water of different quality. Thereat, the soil moisture in the layer of 0-60 cm was in the range of 75–90% of MMHC depending on the soil grading. The highest increase in peach yield (33%), in comparison with the check plot was observed on sod sandy soils in SE "DAF named after Solodukhin" in Kherson region when applying mineral fertilizers. The higher dry matter content in fruits by 2,6% and nitrate content by 29% were also observed when using mineral fertilizers on this farm. The highest yield increase up to 21,16 t/ha on dark chestnut medium loam soils in private joint stock company "Radsad" in Mykolayiv region in apple orchards was obtained when using organic-mineral fertilizers and irrigating with partially suitable water. The yield increase up to 26,81 t/ha was obtained on chornozem southern heavy loam soil in private joint stock company "Kamyanskyi" in Kherson region when irrigating with water suitable for irrigation and up to 32,62 t/ha of yield increase was obtained on dark chestnut medium loam soil in "Bilozerskyi" state farm in Kherson region when irrigating with water suitable for irrigation. Higher dry matter contents were recorded under mineral fertilizers, higher sugar content - under organic-mineral and mineral fertilizers, nitrate content under organic fertilizers. The content of nitrates under different fertilization systems for all fruit trees did not exceed the maximum concentration limit of 60 mg/kg. It was also found out that the highest effect on the yield of perennial plantations had organic-mineral fertilizers with a correlation coefficient of 0,75.The results of mathematical data processing showed that the fertilizers applied along with drip irrigation (fertigation) had a positive effect on the yield of peach and apple trees and the quality of their fruits.