California Farmers Plant Hedgerows to Conserve Water, Improve Soil Health

Hedgerows, also known as liv­ing fences, pro­vide numer­ous ben­e­fits for farms and orchards in California. 

The California Healthy Soils Program funds cli­mate-friendly prac­tices, includ­ing plant­ing hedgerows, which have been found to improve car­bon seques­tra­tion, increase pol­li­na­tors, reduce ero­sion and water con­sump­tion and facil­i­tate insect man­age­ment. All of this reduces costs for olive farm­ers in a low-mar­gin indus­try.

“We have put in about 8 miles (13 kilo­me­ters) of native pol­li­na­tor hedgerows here on the farm-not imme­di­ately in the olives,” Don Cameron, the vice pres­i­dent and gen­eral man­ager at Terranova Ranch, told Olive Oil Times. 

“I believe that any­thing we can do to increase the native pop­u­la­tion of native pol­li­na­tors not only ben­e­fits the olives but a wide range of other agri­cul­tural crops that are depen­dent on insect pol­li­na­tion,” he added.

Terranova Ranch grows var­i­ous crops, includ­ing olives for oil, fruit, veg­eta­bles, nuts and seeds in the San Joaquin Valley, with exten­sive expe­ri­ence grow­ing hedgerows in California.

“We started with a healthy soils grant from the California Department of Food and Agriculture (CDFA) about four years ago,” Cameron said. ​“We applied for and received a grant for a half mile (0.3 kilo­me­ters) of native pol­li­na­tor hedgerows. We were able to extend the length to approx­i­mately 1 mile (0.6 kilo­me­ters).” 

“Now, these plants are well estab­lished and pro­vide excel­lent habi­tat for native pol­li­na­tors along with a wide range of birds, snakes and other wildlife,” he added. ​“We have an abun­dance of hum­ming­birds all sea­son, along with other species that have taken up res­i­dence here on the farm.”

Jo Ann Baumgartner, the exec­u­tive direc­tor of Wild Farm Alliance (WFA), told Olive Oil Times that hedgerows pro­vide a range of ben­e­fits for farm­ers and the envi­ron­ment. 

“Installing hedgerows along field edges sup­ports nat­ural enemy insects, ben­e­fi­cial birds for pest con­trol and pol­li­na­tors for increased pol­li­na­tion ser­vices,” she said.

Besides adding bio­di­ver­sity and beauty to the farm, the shrubs and trees within a hedgerow can also improve water qual­ity, pre­vent ero­sion and store sig­nif­i­cant amounts of car­bon in their tis­sues and the soil. 

Farmers turn to var­i­ous con­ser­va­tion agen­cies, gov­ern­ment, pri­vate and non-profit orga­ni­za­tions for help with hedgerows. The United States Department of Agriculture’s Natural Resources Conservation Service (NRCS) offers a national pro­gram for farm­ers with tech­ni­cal assis­tance and fund­ing. 

The Xerces Society for Invertebrate Conservation pro­vides hedgerow kits, among their native plant species kits, for ranch­ers and farm­ers. WFA assis­tance helps farm­ers with the healthy soil pro­gram appli­ca­tion and part­ner­ing with local resources for hedgerow instal­la­tion.

Cameron noted that they worked exten­sively with Xerces to mon­i­tor species using the hedgerows and to add to their orig­i­nal plant­ing.

Olive grow­ers new to hedgerows can use proven best prac­tices for max­i­mum suc­cess. 

“Make sure to install native plants, as they are well adapted to California cli­mates and ecosys­tems,” Baumgartner said. ​“Native plants also bet­ter sup­port the native insect and bird species that have evolved to uti­lize them, whereas weedy, non-native plants can attract more pests.”

A diverse mix of native plants pro­vides a spread of flow­er­ing and fruit­ing peri­ods, pro­vid­ing food resources for ben­e­fi­cial species for most of the year. 

One hur­dle farm­ers can face is mak­ing enough time to care for a new hedgerow. ​“The first year is crit­i­cal to suc­cess, so make it eas­ier by set­ting up the site for low main­te­nance by using mulch, ver­te­brate pro­tec­tion and a timer for irri­ga­tion,” Baumgartner said.

Baumgartner offered prac­ti­cal tips for low main­te­nance. ​“Add a 6‑inch (15-cen­time­ter) layer of mulch around the plants,” she said. ​“This will help to smother weeds and retain mois­ture. Tree-cut­ting com­pa­nies will often deliver mulch for free.”

She also advised using cages or silt fence fab­ric to pro­tect against deer, rab­bits, gophers and ground squir­rels.

Baumgartner also empha­sized that irri­ga­tion effi­ciency is eas­ier with a timer. ​“If a timer is not pos­si­ble, put plant­i­ngs on the same sys­tem as nearby crops so both are watered at the same time, mak­ing sure that they don’t receive fer­til­izer through that irri­ga­tion water; fer­til­izer makes the plants grow too fast and lodge over,” she said.

According to Cameron, fol­low­ing best prac­tices is espe­cially cru­cial in regions of California where hedgerows strug­gle to grow nat­u­rally. 

“We have found that the orig­i­nal estab­lish­ment can be tricky as for our hedgerows and our cli­mate here in the San Joaquin Valley, the heat can cause dif­fi­culty estab­lish­ing small shrubs and other plant­i­ngs,” he said. 

“Soil prepa­ra­tion, sea­sonal tim­ing, weed con­trol, and irri­ga­tion all influ­ence the suc­cess of plant­i­ngs. It takes work and care to make these projects work,” Cameron added.

On-farm habi­tat is an essen­tial indi­ca­tor of a healthy, resilient farm. People may mis­tak­enly believe that hedgerows will use pre­cious water resources and take away land that could be pro­duc­ing crops.

Baumgartner con­firmed the con­trary. ​“Hedgerows only require irri­ga­tion in the first three years,” she said. ​“After that, hedgerows’ deep roots help with infil­tra­tion and pre­vent runoff dur­ing times of excess rain.”

“As for los­ing valu­able crop­land, tran­si­tion­ing land to per­ma­nent habi­tat helps increase yield in adja­cent crops, pre­vent­ing the loss of over­all crop yields,” Baumgartner added.

According to the CDFA web­site, healthy soil improves plant health and crop yields and increases water reten­tion and infil­tra­tion. CDFA notes that healthy soil can hold up to 20 times its weight in water. Improving soil and con­trol­ling ero­sion is vital to main­tain­ing the integrity of the land, lev­ees and road­sides.

“Once estab­lished, irri­ga­tion and weed con­trol is reduced, and the plant­i­ngs add a ben­e­fit that is aes­thet­i­cally pleas­ing,” Cameron said. ​“It sort of is the fin­ish­ing touch to the farm. The flow­er­ing plants are great to look at and are a nice com­ple­ment to our typ­i­cal row crops and per­ma­nent plant­ing, includ­ing our olives.” 

“I believe that the hedgerows will pro­vide sanc­tu­ary for ben­e­fi­cial insects that will help not only olives but also many other crops grown here in California,” he added. 

The work of plant­ing hedgerows is ambi­tious yet with a com­pelling his­tor­i­cal prece­dence. Baumgartner said the WFA has set a goal of plant­ing 500,000 miles (800,000 kilo­me­ters) of hedgerows in the U.S.

“Historically, Great Britain’s hedgerows could have reached that dis­tance. The U.S. is approx­i­mately 40 times Great Britain’s size, so we can achieve this dis­tance and go even far­ther,” she con­cluded. ​“California grow­ers, includ­ing California olive groves, play a crit­i­cal role in reach­ing this goal.” 

• CDFA