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