Photo by Pam Krone. Property 2, plot T2, September 2020 after 2nd compost application.

Pam Krone, Agriculture Water Quality Coordinator with California Marine Sanctuary Foundation/Monterey Bay National Marine Sanctuary received a Healthy Soils grant from the California Department of Food and Agriculture (CDFA) in spring 2018 to increase carbon sequestration in the soil while also supporting farming and ranching operations. One of the primary activities of this grant was applying compost to grasslands in order to increase carbon sequestration. Grant activities took place over three years from 2018-2020. Compost was spread two years in a row (December 2018 and November 2019) at two properties in coastal Monterey County at a rate of 4 dry tons per acre. The third and final compost application will be in fall 2020. This article calculates the costs associated with spreading compost for two years on grasslands and an oak woodland at these two sites (identified as Property 1 and Property 2).

General Costs

Cost that went into compost application included time costs and cash costs. Costs related to time included time spent researching local compost companies, setting up the plots, and spreading the compost. Cash costs included cost of the compost, transportation of compost to the property, and equipment for spreading compost. For this article I used $27.20/hour as the value of people's time. This number comes from the Independent Sector volunteer rate for July 2020.

Pam noted that there are many different locations for compost on the Central Coast. Some companies charge by the mile to deliver. Some have a set price per ton or cubic yard delivered. Others will provide contact information for delivery services if they cannot deliver themselves. Pam found that it was more economical to go with a supplier who would also provide the delivery and include the delivery price in the overall compost cost. Another finding was that different suppliers have different spreading equipment. And some are more particular about only spreading on flat even ground, while others are more flexible about spreading on uneven or slightly sloped terrain.

Regular cost for compost, delivery, and spreading ranges from $45-$62/ton, depending on what kind of compost is purchased, whether it is certified organic, distance to the property from the compost company, and steepness and evenness of the field. Most companies deliver the compost and do not let people come pick up the compost themselves. Cost for spreading ranged from $7 - $12/ton on flat ground (spreading cost is included in the $45-$62/ton figure above). Costs are higher for spreading compost on steeper land. The Healthy Soils grant program only paid $35/ton for compost. Pam was able to negotiate with the compost companies to get a reduced rate so the grant covered all the compost costs. However, at least one company took a loss, so reduced rates are probably not going to be available the future.

Costs for Property 1

Property 1 is a 17-acre farm that runs sheep, pigs, and chickens. There are eighteen plots across three fields on this ranch (Figure 1), half of which received the compost treatment (labeled as T1, T2, and T3) and half of which were control plots (labeled as C1, C2, and C3), not receiving the compost treatment. Field 1 is grassland and was broadcast seeded with an LA Herne dryland pasture mix in January 2020. Field 2 is an unseeded open grassland, and Field 3 is an oak woodland. Table 1 lists acreage for each plot. Compost was spread across a total of 1.29 acres at Property 1.

Figure 1. Map of Property 1

Figure 1. Map of Property 1

The rancher for Property 1 wanted compost without manure content in order to minimize the application of phosphorus, as chicken and goat manure were already present from grazing the fields. Organically certified compost made from green waste was selected. In 2018 an ATV pulling a small trailer was used for compost addition. The compost was hand shoveled into the trailer, taken to the plots, dropped out the trailer back gate, and raked to achieve even coverage. The time to accomplish this task (approximately 50 hours) lead the rancher to seek an alternative application method the second year. In 2019 the rancher was able to borrow a tractor and manure spreader from a nearby ranch, but had to rent a trailer in order to transport this equipment. The tractor and manure spreader were used for compost application to Fields 1 & 2, which are open grassland and the spreading task was accomplished in one day. Field 3 is an oak woodland and the ATV and trailer were used again for this field. However, the tractor shovel was used to fill the trailer, rather than hand shoveling, and the compost spreading task for Field 3 was accomplished in 8 hours. Table 2 shows costs associated with compost application at Property 1.

Costs for Property 2

Photo by Pam Krone. Property 2, plot C5 on February 2019.

Property 2 is a 38-acre property with sheep and pigs. There were six plots covering 24 acres on this ranch (Figure 2). Plots T2 and C6 were irrigated in 2018. Plots T2 and T3 were irrigated in 2019. Plot T2 was irrigated in 2020. Irrigation occurred one day per week for 4 hours (spaced out at two 2-hour intervals). Irrigation in 2018 and 2019 started in June and was continued through October. In 2020 irrigation began in June and continued through now (end of September). Compost was added to three treatment plots: T1, T2, and T3. The three control plots did not receive compost: C4, C5, and C6. Plots are approximately equal in size, as specified by the CDFA grant, each covering about 4 acres for a total area of 12 acres receiving compost at Property 2. Table 3 shows costs associated with compost application for Property 2. The compost company that Property 2 went with would not spread the compost because the slope was too steep. The owners of Property 2 have a tractor and manure spreader that was used for the compost application.

Figure 2. Map of Property 2

One of the anticipated benefits of compost addition is higher forage production. Peak standing biomass was measured on all plots at both properties in the spring of 2018 (prior to compost application), 2019, and 2020. However, forage production was not measured in Property 1 Field 3 in 2020 because there was too much poison oak. Based on these measurements, biomass increased on all compost plots and decreased on all control plots after compost application. It is important to note that increased forage production may or may not be a direct cause of the compost application. Other factors such as weather, irrigation, and seeding can substantially influence forage production. Interestingly, forage production in the control plots decreased. It is typical for forage production to change each year, depending on timing and amount of rain. If the increase in forage production on the compost plots was due to weather, it would be expected that forage production on the control plots would increase as well, but this did not occur. Therefore, it is reasonable to hypothesize that the increase in forage production on the compost plots was due to the compost application.

The owner of Property 1 noted that there was one unidentified tall plant (not a grass) that grew only on the plots where compost was applied. And the owner of Property 2 observed that the compost fields were more lush and stayed green for longer. A research project with an appropriate experimental design would be required to understand the value of compost in improving forage production.

UCCE San Luis Obispo County is hosting a one-hour Zoom workshop covering the following topics:

• Forage Production and Nutrient Quality
• Trace Mineral Supplementation
• Toxic Plants
• Healthy Soils / Composting
• Yeomans Plow
• Grazing Reduces Wildfire Risks & Severity

Date: Tuesday, September 29, 2020

Time: 4:00 to 5:00 pm

Location: Zoom

Cost: Free

To Register click here or Or call Hiromi at 805-781-5940.

Click here to see the flyer.

This is a summary of forage production clipping from 2020.

I was able to clip forage production at two sites in San Benito County: one in Rainfall Zone A and the other in Rainfall Zone B. Click here to see the Rainfall Zones. 

Table 1 shows two forage production values for each rainfall zone. The two forage production values are as follows:

1. The NRCS Web Soil Survey estimate of forage production in a normal rainfall year. The NRCS value is considered to be the typical amount of forage that will be produced in a normal rainfall year. Therefore, this year's estimates will be compared to the NRCS estimate.
2. Forage production clipped this year (2020).

The last column in the table shows how different this year's production is compared to the NRCS estimate for a normal rainfall year. A plus sign before the number indicates that this year's forage production was higher than the NRCS estimate and a minus sign before the number indicates that this year's forage production was lower than the NRCS estimate.

Table 1. 2020 San Benito County Forage Production

* NRCS forage production data were not available for this site, so forage production from an adjacent soil type was used.

In 2020, forage production in Zones A and B was substantially higher than the NRCS estimates (220% and 290% respectively). Forage production in Zones C, D, and E were not measured.

Forage production was clipped on May 8, 2020. Average annual rainfall (from 1994-2017) for San Benito County according to CIMIS Weather Station #126 in Hollister, was 14.42 inches. CIMIS reported 10.9 inches for this station from October 2019 – May 2020. According to the San Benito County RAWS weather station at Pinnacles National Park, average annual rainfall (from 2001-2017) was 9.83 inches. The Pinnacles RAWS station reported 11.79 inches for from October 2019 – May 2020. Rainfall was lower than average this year in the northern part of the county, but higher than average in the central part of the county. The rainfall started slow this year with no rainfall in October. It rained some in November and picked up in December, but declined again in January. In February as with October, there was no rainfall. March picked up again, with less in April and almost no precipitation in May.

From a grazing perspective, a rancher from the northern part of the county said that the amount and quality of feed for the year were good because of two substantial rain storms that led to a "miracle March." However, there was very little feed early in the season which resulted in calves that were substantially lighter than they would have been in a year with more rain and feed early in the season. A rancher from the central part of the county said this year was probably better than average and that the quality of the feed was good. On the other hand, a rancher from the southern part of the county felt that this year was about average. Although the growth was good, the nutritional quality of the forage was lacking. This rancher started supplementing earlier and heavier than normal.

The San Benito County Weed Management Area (WMA) is planning the Continuing Education Seminar for Ranchers which is normally held at the Vets Hall in Hollister in early December.  Since health guidelines will likely not allow us to hold a large in-person meeting this year, our team is exploring an on-line option for this year's seminar.  In order to plan a meeting that will best meet the needs of area ranchers, we really need to hear from you!  If you are a San Benito, Monterey, Santa Cruz, or Santa Clara County rancher that has attended or planned to attend the annual Ranchers Seminar in Hollister, please take a couple of minutes to complete a short survey at this link.

OR, if you prefer to reply by email, please send your responses to the following questions to karminder.brown@gmail.com. (Responses will be kept confidential and used only to help the WMA plan the 2020 Ranchers Seminar):

1. Would you plan to attend an on-line (virtual) Ranchers Seminar tentatively scheduled for Thursday, December 3^rd?

YES   NO

2. If YES:

Would you join the webinar from a computer, tablet or smartphone?

OR

Would you join the webinar by dial-in phone with audio only? (This option might mean that you would be ineligible to earn continuing education credits from DPR).

3. If YES:

Would you still plan to attend if no DPR continuing education credits/hours were offered?

4. If YES:

Which specific weed or pest management topics would you like to have covered at the seminar?

5. If NO, why not?  (Choose all that apply).

My internet access is limited or unreliable 

I am unfamiliar with Zoom and other webinar platforms

I'm not available on that date

I don't need DPR continuing education credits

Other: ________________________________

Thank you for taking a few minutes to help the San Benito WMA team to plan the 2020 Continuing Education Seminar for Ranchers.  We'll keep you posted as plans for the meeting shape up.