Response of pea plants (Pisum sativum L.) to phosphorus levels and humic acid levels

Two field experiments were conducted to evaluate the effects of phosphorus level and humic acid on pea (Pisum sativum L.) yield quantity and quality, under drip irrigation system, during 2011 and 2012 seasons. Experiments were carried out in the Research and Production Station, National Research Centre, El-Nobaria Site, Beheara Governorate, Delta Egypt. Phosphorus fertilizer was applied at rates of 0, 40, 80 and 120 kgP2O5 ha -1 before planted and humic acid at three levels (0, 5 and 10%) as foliar spray. Plants were sprayed two times with humic in intervals of 30 and 45 days from sowing. The obtained results could be summarized in the following: Growth and yield parameters were significantly increased by increasing phosphorus levels. Dry weight, weight of 100 seeds and yield were significantly increased by increasing of humic acid levels. The combination between phosphorus at 80 kgP2O5 ha -1 and humic acid at rate 10% gave the highest growth and production as well as minerals composition (N, P, K, Fe, Mn, Zn and Cu) and protein content compared to other treatments. Humic acid decreased soil pH and increased the availability of phosphors and micronutrients.