Soil conditions contribute to poor plant growth
Print
EmailEditor’s note: This article is from the archives of the MSU Crop Advisory Team
Alerts. Check the label of any pesticide referenced to ensure your use is
included.
This article was originally published in the June 25, 2008 issue of the Vegetable CAT Alert.
The recent heavy rains have provided challenging soil conditions. Soils
are compacted by intense rainfall and standing water. Excess water tends
to seal the soil surface, even on some sandy soils. These conditions
impede drying of the soil and movement of air into the soil. The root
environment is oxygen deficient and roots cannot function properly to
take up water and essential nutrients. Many beneficial microorganisms
also have a difficult time functioning when oxygen starved. When these
conditions persist for more than two to three days, roots will become
non-functional and may begin to degrade. Cultivation is essential to
open the soil and allow air to move in. Renewed aeration of the soil
will stimulate root growth and microbial activity that will mineralize
nitrogen and other nutrients. With aeration, new root growth will occur.
During flooded or saturated soil conditions 50 lbs N/a or more may be
lost by leaching or denitrification. Once soils dry sufficiently,
sidedress 40 lbs N/a to enhance root and plant growth. Spraying nitrogen
and other nutrients on the foliage of stressed plants may help them get
through the stress period. However, under stress conditions plants are
less able to absorb nutrients through the leaves, so the benefit may not
be as great as anticipated. Urea ammonium nitrate (28 percent nitrogen)
is a good source of nitrogen for foliar application as long as the rate
does not exceed three gallons per acre. Small amounts of nutrients may
be able to be added in with other spray materials, but be sure to check
compatibility.
When excess rainfall occurs, the primary nutrient of concern is usually
nitrogen. In sandy soils, significant amounts of potassium may also be
leached out of the root zone so that topdress application may be
beneficial for high potassium requiring crops, celery and tomatoes.
Boron is also subject to leaching out of the root zone in sandy soils
and muck soils. For celery, celeriac, broccoli and root crops consider
spraying 0.25 lb actual boron per acre on the foliage.
