The fifth biochar test plot of Growing with Biochar was installed at Common Ground Local Food Project on Saturday, June 22. This KAW Valley Biochar project is funded by a 1-year Farmer-Rancher grant from USDA Sustainable Agriculture Research & Education (SARE). Eight on-farm test plots will be created to demonstrate proper use of biochar in carbon-smart farming.
|Common Ground Local Food Project
Sustainable Agriculture Education, Johnson County Community College
June 19 Common Ground Local Food Project in northeast Lawrence was visited by research field agent Devin Gerling and coordinator David Yarrow. Common Ground is growing vegetables a second year on an acre at 815 Oak Street, nearly on the Kansas River bank. Soil is sandy silt river deposits. Sparsely growing weeds suggest soil is weak, tight, low in carbon, calcium, nitrogen, phosphorus, trace elements.
Professor Stuart Shafer, Chair of Sustainable Agriculture at Johnson County Community College (JCCC), began Common Ground in 2012 to teach sustainable agriculture to JCCC students. Stu has 35 years experience in organic farming, an MA in Sociology from Univ. of Kansas, Candidate of Philosophy in Sociology from Univ. of California San Diego. The lot is supplied by municipal water from a hydrant, and drip irrigation system. Produce is mostly marketed through Rolling Prairie Farmers Alliance CSA. 50% of harvest is donated to Just Food food bank in Lawrence.
measures & marks first test bed
Test Bed #2
dry, uninoculated BioChar'ge
Test Bed #3
Devin sprinkles sea solids
Stu will plant Sweet Potatoes in the test plot. Once again, we had to adapt the standard test plot design to the reality of farm and crop. Stu planned to plant three rows of sweet potatoes, each row the full width of the lot, which Devin measured as 80 feet. Stu imagined applying biochar in narrow strips, then rototilled into the root zone. This meant 12, maybe 15-inch wide strips.
|Test Bed #2
Test Bed #3
Test Bed #3
with sea solids
Stu's plan mixes biochar in soil around a plant crown bud where tubers form. Biochar, minerals and microbes will significantly loosen and open soil for tubers to swell easily. But hair-like feeder roots extend far more widely throughout the soil, scouring up water and nutrients to send to the tubers to be stored. Stu's strategy will not deliver strong nutrients to those feeder roots. Additional action is needed to adjust nutrient levels and availability in soil beyond the 12-inch strip.
We agreed to create three test beds, each 12 inches wide, 80 feet long, separated by 4 feet. Sweet potato slips will be planted in three straight, 80-foot rows, with drip irrigation. From north to south, the three test beds are:
1) Control: fertilizer only
2) BioChar'ge only: raw, dry
3) BioChar'ge plus: incculated+sea solids
The next day, Devin and I prepared a batch of inoculated biochar. This time we brought two 30-gallon trash cans to the test plot, which is right by a water faucet. We divided 30 gallons of BioChar'ge oak biochar between the trash cans, added equal water, and stirred in three quarts of SCD BioAg.
Two days later, we returned with another 30-gallons of BioChar'ge. Devin measured and marked three 80-foot-long test beds, then dug six-inch-deep holes to take soil samples. Given the weak soil and spotty plant growth, significant amendments may be needed. Soil tests will identify major mineral or trace element deficiencies, and enable us to formulate extra nutrients for the sweet potato crop.
We applied raw and inoculated BioChar'ge in 12-inch wide strips. Devin then scattered SEA-90 sea minerals on the inoculated char. Given the obviously poor soil, I told Devin to apply a stronger dose of sea minerals—over 4 cups on the 80-foot test bed.
The west third of the designated row
This test plot is a single
|Completed Test Beds
rototilled & planted, with drip irrigation