Abstract: The total amount of straw resources is large with great potential for utilization. Straw, fertilizer and water retention gel were composited of straw/water retention gel slow-release brick fertilizer, whichcan be used to expand the application for straw fertilize. A water retention gel was prepared from low-cost potato starch, mixed with agricultural waste wheat straw powder after gel fertilization, and pectin was added as a binder to obtain a straw/water retention gel slow-release brick fertilizer by pressing. The water retention and water holding properties of the fertilizer bricks were investigated, and the potential of brick fertilizer in vegetable cultivation was studied through potting experiments. The study showed that the maximum water holding capacity of the soil can reach 72.45% with the addition of 4.00 g of slow-release brick fertilizer, and the equilibrium water retention can reach 10.72%. The nutrient release cycle of slow-release brick fertilizer reaches 24 days, and the nutrients remain unreleased on the 24th day is 13.89%. Cilantro treated with the slow-release fertilizer bricks exhibits the best growth with 1,2 more leaves, the plant height is 3.0~6.0 cm, and the root length 1.0~2.0 cm compared to those not treated with chemical fertilizers or treated with urea.

Key words: brick fertilizer, straw, water retention gel, water retention and holding, slow-release performance