Reducing the hazardous effect of mineral nitrogen fertilizers on pepper production by using compost and compost extract in saline soil

A field experiment was carried out during two successive seasons; 2015/16 and 2016/17 at Gilbana village of Sahl El-Tina, North Sinia Governorate, Egypt. The objective of this study was to evaluate the environmental risk of mineral nitrogen fertilizers on soil water table and plant, Compost and Compost extract were used as complementary application. This experiment was designed in a Randomized Complete Block Design with three replicates. Two sources of nitrogen fertilizers are used in the experiment ((NH4) 2SO4 & NO3NH4). The treatments were T1-100% Recommended dose of ammonium sulphate (140 kg. N / fed), T2–75% of recommended dose of ammonium sulphate (105 kg. N/fed) (1 feddan (fed) = 4200 m² = 0.42 hectares = 1.038 acres) and Compost at the rate of (2 t fed-1), T3 – 50% of recommended dose of ammonium sulphate + Compost at the rate of (4 t fed-1), T4 - 100% Recommended dose of ammonium nitrate (140 kg. N/fed), T5 – 75% of recommended dose of ammonium nitrate (105 kg. N/fed) and Compost at the rate of (2t fed-1) and T6 – 50% of recommended dose of ammonium nitrate (70 kg. N/fed) + Compost at the rate of (4t fed-1). The results indicated that the addition of the fertilizer requirements as (Ammonium sulphate and Ammonium nitrate) by 100% (140 kg. N/fed) of each, produce (6.4 and 9.0) ton/fed of pepper production in the first season; respectively, in the second season, were (7.4 and 9.4) tons / fed; respectively. On the other hand, T3 (50% Ammonium sulphate (70 kg. N/fed) + 50% compost) was the superior treatment for pepper production, and the lowest contamination of nitrates and nitrite in pepper fruit and loss in ground water.