Orchard Compaction: A Pressing Problem

A compacted “plow pan” layer often forms about 8 to 10 inches below the surface in both mowed and tilled orchards. This is a widespread problem in orchards regardless of soil type. Growers are often unaware of its presence and impact. In some cases, no-till orchards haven’t been ripped for decades.

Just ask Mark Schmidt, who grows almonds and walnuts in Waterford, CA, located in the northern San Joaquin Valley. He has one block of 20-plus-year-old walnuts that has sandy top soil, but just about 8 inches down a hard pan, or plow pan, has formed. “Just doing normal work on the ground over the years compacted it down,” he says.

Last spring, Schmidt deep-ripped the orchard, and the results were dramatic. “In one year, the growth was just unbelievable, from 1 foot a year, to 3 to 4 feet this past year,” he says. “It was all because of the compaction; the hard pan was cutting off the roots. The roots were just getting by.”

Schmidt, who’s also known in the ag community as a beekeeper, certainly learned a lesson he won’t forget. “This year I ripped that ground both ways; last year I ripped it just one way,” he says. “I did a real massive break-up job this time.”

 

Let Roots “Breathe”

A greater understanding of soils and the effect of compaction on tree growth and yield will help in developing approaches to minimize the problem and increase productivity. Soils are complex mixtures of mineral particles that vary in both size (sand, silt, clay) and arrangement. Soil texture refers to the proportion of sand, silt, and clay in a soil. Soil structure means how the particles are arranged; it largely determines the amount of pore space, the spaces between the particles, in the soil.

Pores are an important part of healthy soils for several reasons. They affect water intake and movement through the profile, the amount of water soil can hold for use by the tree, and drainage below the root zone. Soil water content increases above compacted layers and may create conditions that encourage root and crown diseases. Compacted soils are more subject to runoff and erosion.

We have seen a number of orchards where the ground was wet in the top few inches but water never reached the roots.

Compaction also affects air exchange between the soil and the atmosphere. Did you know that roots need to “breathe?” Roots and the beneficial microorganisms that live in the soil need to take in oxygen and release carbon dioxide.

Microorganisms fix nitrogen from the air and help break down organic matter which releases nutrients to the tree. These are important points to keep in mind because cultural practices have a direct impact on soil quality and sustaining tree health.

 

Lighten Up

As Schmidt learned, soil becomes compacted primarily because of the pressure applied by the weight of orchard equipment. It compresses the soil particles together, causing the soil to be denser with less pore space. It is more difficult for roots to push through dense soil and so root growth can be reduced. The best strategy to minimize compaction is to prevent it from occurring in the first place. The risk for compaction is greatest when soils are wet. Driving on wet soils is the single biggest cause of compaction.

A dry soil is much more resistant to compaction than a moist or wet soil. Sandy soils are particularly susceptible to compaction as the weight of equipment can cause the sand grains to interlock. Soils with high organic matter are also less susceptible to compaction. Test for compaction by probing the soil with a pointed metal rod, bucket auger, soil tube, or shovel. It is more easily done on a somewhat moist soil.

Apply even pressure and push the probe into the soil. Compaction is the resistance found about 8 to 10 inches below the soil. Alleviate compacted layers by ripping or chiseling when the soil is dry. A shank depth capability below the compacted area is necessary. Curved shanks require less draft than straight shanks to loosen the same amount of soil. Space the shanks no further apart than the depth of ripping and cover the width of the middle to within a few feet of the trunks to avoid injury to larger roots. A single shank down the middle is of limited value. Do not worry about injuring smaller roots; root pruning actually stimulates root growth in much the same way that heading cuts in the canopy promote new shoot development.

For nine ways to minimize compaction, go to the next page.

Pages: 1 2

Topics:

Leave a Reply

Nuts Stories
Disease ControlNew Fungicide For Wide Range Of Fruits, Vegetables In California And Florida
April 21, 2015
FMC officially enters biological marketplace with first sales of Fracture fungicide. Read More
NutsPart 2: Spring Weed Management Tips For Almonds: Reduce Herbicide Resistance
April 14, 2015
Follow these tips to help improve long-term efficacy of herbicides. Read More
NutsPart 2: Combating Navel Orangeworm: IPM Approaches to Reduce Pyrethroid Resistance
April 14, 2015
Follow these IPM approaches to reduce unnecessary sprays and manage pyrethroid resistance. Read More
NutsPart 1: Spring Weed Management Tips For Almonds
April 8, 2015
Avoid common weed management mistakes to ensure optimum weed control in the orchard. Read More
NutsPart 1: Combating Navel Orangeworm: Pyrethroid Considerations
April 8, 2015
Proper use of pyrethroids is critical for maintaining the broad-spectrum pesticide’s efficacy. Read More
CitrusCalifornia Snowpack Is Virtually Gone
April 2, 2015
With the lowest water content since 1950, the governor orders first-ever mandatory water reductions in cities and towns, and growers face tighter regulations. Read More
CitrusMake Every Day Ag Day
March 31, 2015
Another National Ag Day came and went on March 18. Did you do anything to promote it this year? Even Read More
The Latest
FruitsOverturned Truck Dumps Millions Of Bees On Highway
April 22, 2015
The truck with 448 hives was headed to a farm in Washington. Read More
CitrusRecord Number Of Organic Producers In U.S.
April 21, 2015
USDA’s Agricultural Marketing Services says domestic production has increased by 250% across all markets since 2002. Read More
FertilizerVerdesian Life Sciences Introduces New Phosphite-Free P…
April 21, 2015
Product designed as alternative for nut and stone fruit growers with concerns about MRLs. Read More
Disease ControlNew Fungicide For Wide Range Of Fruits, Vegetables In C…
April 21, 2015
FMC officially enters biological marketplace with first sales of Fracture fungicide. Read More
NutsPart 2: Spring Weed Management Tips For Almonds: Reduce…
April 14, 2015
Follow these tips to help improve long-term efficacy of herbicides. Read More
NutsPart 2: Combating Navel Orangeworm: IPM Approaches to R…
April 14, 2015
Follow these IPM approaches to reduce unnecessary sprays and manage pyrethroid resistance. Read More
NutsPart 1: Spring Weed Management Tips For Almonds
April 8, 2015
Avoid common weed management mistakes to ensure optimum weed control in the orchard. Read More
NutsPart 1: Combating Navel Orangeworm: Pyrethroid Consider…
April 8, 2015
Proper use of pyrethroids is critical for maintaining the broad-spectrum pesticide’s efficacy. Read More
CitrusCalifornia Snowpack Is Virtually Gone
April 2, 2015
With the lowest water content since 1950, the governor orders first-ever mandatory water reductions in cities and towns, and growers face tighter regulations. Read More
CitrusMake Every Day Ag Day
March 31, 2015
Another National Ag Day came and went on March 18. Did you do anything to promote it this year? Even Read More
Laboratory beakers
CitrusGrowing Demand For Magnesium Nitrate Spurs TradeMark Ni…
March 30, 2015
Via enhancements made to its manufacturing plant, Florida company is able to provide more of its product to various fertilizer distributors and retailers throughout the country. Read More
blue orchard bee
Integrated Pest ManagementBlue Orchard Bee Shows Promise As An Alternative Pollin…
March 30, 2015
The native bee Osmia lignaria could soon be a valuable piece of the pollinator mix, especially for smaller almond growers. Read More
NutsWhy You Should Use Low-Rate Applications Of Potassium
March 26, 2015
These rates provide growers a low-cost method comparable to conventional applications. Read More
Disease ControlBacterial Spot Can Make Almonds Unmarketable
March 24, 2015
Management strategies can help you mitigate losses from this nasty almond disease. Read More
CitrusFarm Bureau Says WOTUS Rule Would Ignore Exemptions
March 24, 2015
Common farming practices may be vulnerable to Clean Water Act enforcement under the rule. Read More
NutsIndustry Update: American Pistachio Growers 2015 Confer…
March 23, 2015
Industry flying high as a billion-pound crop looms at the end of the decade. Read More
CitrusCalifornia Unveils $1 Billion Drought Package
March 23, 2015
Governor, legislative leaders, announce $1 billion emergency drought legislation. Read More
CitrusFeed A Bee Campaign Aims To Plant 50 Million Flowers
March 23, 2015
Bayer CropScience announces program to increase forage opportunities for critical pollinators. Read More