Deep Zone Tillage (DZT) at the Dzen’s Farm, Ellington, CT: Case Study III

By: Jude Boucher, UConn Extension and Donny Dzen

Farm History, Crops & Markets:  The Dzen’s Farm is comprised of about 300 acres with fields in Ellington, South Windsor and East Windsor.  Don and Joe are the third generation on a farm originally purchased by their grandfather in the 1930’s to raise dairy cows, potatoes and tobacco.  Today, they raise about 150 acres of Christmas trees, 50 to 60 acres of pumpkins, a similar amount of straw mulch, 25 acres of strawberries, 20 acres of blueberries, 6,000 mums and greenhouse bedding plants.  Don and Joe have farmed all their lives and began co-managing the farm in 1992.  The majority of the crop is sold through wholesale channels, but pick-your-own and retail sales at their farm stand account for most of the profits.

Soils and Soil Health Issues:  The Dzen’s farm a variety of beautiful, mostly rock-free, CT River Valley soils: silt loams, sandy loams, and fine sandy loams.  Prior to adopting DZT, all their fields were tested for compaction with a penetrometer and four Soil Health Tests identified problems with aggregate stability in one field and active carbon and mineralizable nitrogen shortages in three or four fields, respectively.  Less critical, but still substantial problems existed with other physical and biological indicators of soil health, such as available water capacity, surface (crusting) and subsurface (plow pan) hardness, low total organic matter and plant roots of low to medium health.

Rational for Adopting DZT:  Don and Joe rotate their pumpkins with land that has been in canary grass or winter rye which is used for straw mulch on their strawberries, or with land that is coming out of strawberry production.  They have traditionally raised the pumpkins with conventional tillage methods, using a combination of herbicides, cultivation and hand hoeing to control weeds.  Since other growers were reporting substantial savings in field preparation time (66 to 83% reduction) and fuel savings (72 to 77%) using DZT, Don and Joe decided to convert their pumpkin production to reduced tillage to improve drainage, reduce disease and save money.  Penetrometer readings showed much of their land had plow pans and they had experienced some problems with water drainage and Plytophthora crown and fruit rot.

Equipment, modifications and procedure:  Don and Joe purchased a second-hand, two-row, Unverferth Zone Builder from a local supplier.  They removed the tools on one side of the machine to create a single row machine capable of preparing different row spacing for different size pumpkins.  They also installed a row maker to help assure consistent spacing between rows.  A single row machine can be pulled with a 35-40 horse power (hp) tractor, but they used their 55 hp John Deere.

Fertilizer was applied to the field in three separate applications:  75# of potassium was bulk spread the previous fall, 30-40# of N and K were banded during planting, and 30-40# of N were spun on just before the vines started running.  Winter rye was allowed to mature until pollen shed and then was cut, dried, and bailed to produce mulch for the strawberries.  The DZT machine was then used to prepare narrow seedbeds through the stubble for planting.  A pre-emergence herbicide (Strategy) was combined with one quart of Round Up and applied to the rye stubble to kill small weeds that had already emerged while the rye matured, and to prevent weeds from emerging in the pumpkins.  Two fields with nutsedge and ragweed problems also received an application of Sandea post-emergence.  Pumpkin fields were not cultivated in 2011.  Approximately 80 growers attended a twilight meeting at the Dzen’s farm last July and had a chance to see Don and Joe’s first few attempts at planting pumpkins using DZT.  Plantings got better as they gained experience.

Early Experiences:  2011 turned out to set another new record for rainfall with over 70 inches of precipitation for the year.  June, August and September were exceptionally wet months, which included tropical storms Irene and Lee that each dropped up to 5 to 10 inches of rain on the central and western portion of the state, and the season came to an abrupt close with the infamous “Halloween snowstorm.”  Don confessed that with three weeks of rain in June, they would have never been able to plant their pumpkins if they had still been using a plow and harrow, as fields would have become impassable.  They were also delighted not to sink in mud while harvesting pumpkins after two tropical storms and were even able to transport the filled bins out of the field without sinking a tractor or truck thanks to the undisturbed cover crop surface on their fields.  They experienced good yields in a terrible year for pumpkin production, a tremendous amount of time was saved by reducing tillage and eliminating cultivation, and the DZT saved the pumpkin crop in a very wet year!

Improvements for the future:  Don learned to check that his planter is actually planting seeds after leaving one field sparsely populated.  After using DZT for a few years to break up the plow pan in their fields they will consider making the transition all the way to no-till to further reduce tillage.

Advice for other growers:  We should have made this switch earlier and you should too.  DZT helps you get into fields that you just couldn’t farm if they were plowed.  It also helped drain the standing water off our fields and most certainly reduced the amount of disease on our pumpkins.  It is also much faster than conventional tillage.