Use of Amendments to Reduce Water Requirements for Stand Establishment of Small-Seeded Crops

Soil crusting after planting is a serious problem in stand establishment of small-seeded crops in the Southwest. When crusting occurs in a saline, warm soil, stand establishment problems are especially severe. It is customary to use costly irrigation water to keep seedbed surfaces moist after planting to reduce soil crusting and to lower soil temperatures. Phosphoric acid (24% and 12%) and sulfuric acid (95%) were evaluated to determine their effectiveness in reducing soil crusting and reducing the amount of water required to obtain stands of sugarbeets, alfalfa, wheat and barley. Phosphoric acid, applied in 4-6 cm bands over the seed row at planting and before irrigation, reduced crusting and increased sugarbeet and alfalfa seedling emergence. Emerged seedlings from phosphoric acid treated plots were larger and one irrigation (10-15 ha cm/ha) was saved in stand establishment. Sulfuric acid applied in bands reduced soil crusting. Soluble salts in the seed zone resulting from band application of sulfuric acid killed or damaged seedlings. Sulfuric acid, when applied in irrigation water to saline-sodic soils, improved plant growth and water use efficiency