Abstract: | Gel-forming, cross-linked polyacrylamides are new formulations of soil conditioners for use where short-term or persistent drought inhibits plant growth. Most commercial products absorb water to many times their own weight thus improving the water storage properties of porous soils, and delaying the onset of the permanent wilting percentage where evaporation is intense. However, there is notable variation between products in the binding tension of absorbed moisture, so changes in field capacity are of little diagnostic value for the soil moisture available to plants. Nevertheless, polymers with high absorption capabilities and low binding tensions in the range pF 2 to 4.2 could be important aids to growth of agricultural, horticultural and forestry crops in drought-prone environments. |