干旱区生态环境知识资源中心

The increasing water demand and the lack of natural resources in arid and semiarid areas justify the present interest in the use of treated wastewater. Since 1995 purified urban wastewater from Almeria (southeast Spain) has been used to irrigate greenhouse crops. The higher nutrient contents of these effluents requires special management strategies. This work studies the effect of irrigation water quality and NK rates, applied by fertigation, on yield and quality of pepper. The experiment was carried out in greenhouse with pepper crop 'Aifos', on a sand-mulched sandy-loam soil and drip irrigation. The experimental design was a two-factorial with four randomized blocks. The treatments applied were the result of a combination of two irrigation water qualities and two NK dosages. The irrigation water qualities were purified wastewater and groundwater. The NK dosages were without additional fertilization, only the contributed for irrigation water (0NK) and the recommended rate (100NK). The recommended rate corresponding to 12.5 g m(-2) of N and 19.3 g m(-2) of K and average nutrient concentrations: 9.8 mol m(-3) of N (NO3-+NH4+) and 5.4 mol m-3 of K+). The dry matter content of fruit, number of fruits, fruit weight per period, weight per fruit, and unmarketable fruit were monitored. Fruit quality was evaluated measuring firmness, total soluble solids, pH, and titratable acidity. The use of wastewater produced no adverse effects on the yield and fruit quality. The NK fertilization has shown positive effect on marketable yield of fruits, effect caused by an increase in early yield and number of fruits. The NK fertilization has not shown effect on attributes of fruit quality harvested in green or red.