The Role of Poultry Manure and Humic Acid in the Water Consumption, Nitrogen Availability, and the Summer Squash Plant (Cucurbita pepo L.) Yield

Abstract

A field experiment was carried out during the spring season 2019-2020 in sandy loam soils, to study the role of poultry manure and Humic acid in the water consumption of Summer squash crop or nitrogen availability under the drip irrigation system. Poultry manure was added to the soil at four levels 0, 5, 10, and 15 ton.ha-1.Summer squash seeds were planted in the field on beds with a distance between one bed and another 0.50 m and the distance between one plant and another 0.40 m. Then, humic acid was sprayed at a concentration of 0 and 4 g.L-1twice, the first after the emergence of the true leaves of the plant, and the second was added before the flowering stage. The study treatments were distributed using the split-plot system according to the Randomized Complete Block Design (RCBD) with three replicates. Soil water retention capacity increased by 13.9%, water consumption was 370 mm, and rationalize irrigation water by 28.2% when poultry manure was added at the level of 15 tons. ha-1. The available nitrogen concentration increased with increasing the level of addition and the highest average was 98.10 mg.kg-1. Humic acid spraying increased the available nitrogen concentration, which reached 91.56 mg.kg-1. The highest yield was 19,232 tons. ha-1and the highest water use efficiency was 6.310 kg.m-3 at the level of addition of 15 ton.ha-1, while spraying with Humic acid led to an increase of 5.64%.