By Mark Licht and Angie Rieck-Hinz
Early-season field conditions can set the tone for the entire growing season. Two common soil issues that can limit early crop development are soil crusting and sidewall compaction. While they look different in the field, both restrict crop establishment and early root growth, reduce early vigor, and can make crop stress symptoms show up sooner and more severely.
What Is Soil Crusting?
Soil crusting occurs when the soil surface seals over after rainfall, forming a dense layer that restricts seedling emergence and limits oxygen and water movement into the soil. Crusting is most common in fields with excessive tillage where soil structure is destroyed. Crusting is also common in fields with little residue left on the surface to reduce raindrop impact that dislodges soil particles and causes them to settle into pores, also causing soil sealing. Crusting often follows intense rainfall shortly after planting and can be found in fields with naturally low organic matter or fine textured soils. When seedlings push through crusted soils, emergence may be uneven, and stands may be reduced. In soybean watch for corkscrewed or broken soybean
hypocotyls. In corn, watch out for leafing out underground. Early season plant population assessments should be completed to evaluate if replanting is necessary. Even when plants break through, restricted early root growth can limit access to moisture and nutrients.
What Is Sidewall Compaction?
Sidewall compaction forms when planter openers smear and compact the sides of the seed furrow, most commonly when planting occurs under wet soil conditions. Instead of roots spreading laterally into the surrounding soil, they often follow the compacted furrow down, creating a restricted, “root-in-a-slot” growing pattern.
Source : iastate.edu