Potassium polyacrylate

Potassium polyacrylate is a potassium salt of polyacrylic acid with the chemical formula [−CH2−CH(CO2K)−]n. As a type of superabsorbent polymer, it can absorb hundreds times its original weight in purified water.
Different from sodium polyacrylate, potassium polyacrylate can be used as water retaining agent in agriculture and won't cause soil salinization.
Uses.
Water retaining agent.
As a type of superabsorbent polymer for plants (Ag-SAP), potassium polyacrylate can increase moisture availability to plants.
It mixes with soil to increase the soil’s capacity for holding water (with water gel form which stay in soil for months) and making it available to plants. This improved soil readily releases moisture, along with water-soluble nutrients, to plant roots on demand. The specific retention of potassium polyacrylate is weaker than roots of most plants.
It can be used in seed coating, grow seedlings, planting crops, topdressing for crops, planting/transplanting trees, flower transport etc.
Mechanism.
Potassium polyacrylate works similar to a sponge under the soil surface. It is composed of a set of polymeric chains, which are linked together chemically to become a water-insoluble, net-like matrix that gently attracts and holds hydrogen molecules. The immense size and weight of its molecular structure allows each potassium polyacrylate granule to absorb over 500 times its original weight in purified water.
It does not ‘bind’ water tightly. The potassium polyacrylate granules release just the right amount of water in response to a plant’s root suction. There is no waterlogging or other ill effects caused by ‘free’ water filling air cavities in the soil.
Potassium polyacrylate maximizes plant growth by reducing plant stress. It also absorbs and releases soil nutrients, water-soluble fertilizer and chemicals in the same manner as water, creating a healthy microenvironment in the plant root zone. The result is faster germination, quicker emergence of seeds, consistent growth and higher, better-quality yields of edibles with less water and fewer inputs.
As a soil amendment, potassium polyacrylate can improve the soil water holding capacity.