Church Pivot Update #2 — Regenerative Land Solutions

We recently clipped and weighed for the church pivot to monitor growth rates for our trial. To catch up on the Church Pivot read more here. The short story is that we split an alfalfa/grass field in half and in the spring of 2020 after seeding we treated one side with the conventional chemical fertilizer program, and the other side with biologicals, fish fertilizer, and a less salty P product. We also added a fall application of biologicals and fish fertilizer on the biological side in September of 2020. Biological programs work well in the fall as they can build from application until the ground freezes and then wake up early in the spring.

On April 20th 2021 we applied 19-30-10-10 at 145 lbs / acre on the conventional side. We applied 1 gal of Provide and 1 lb of Revive plus 1 gal of fish fertilizer on the biological side on May 19th. The conventional application was $43.44 / acre and the biological application was $29.01.

We weighed both sides of the field on June 2nd, just after the Provide/Revive had been applied.

With guidance from our local NRCS office, we randomly tossed a production sampling hoop 3 times on both sides. We let the hoop fall naturally by including plants when the base of their stem is inside the hoop and removing plants when the base of their stem is outside the hoop.

We then clipped all foliage at ground level and separated the species. We weighed alfalfa and orchard grass and discarded any non-production weeds. Then, we weighed each with a 300 g scale. You may have to weigh your vegetation in multiple chunks and add these together given the weight limit of the scale. Once you have the total grams of Green Weight you can begin the calculation below.

Green Weight x 20 (hoop conversion factor) = Y lbs/acre green weight

There are 43,560 sq ft in an acre. Our hoop encloses 4.8 sq ft. 4.8/43,560 = 0.00011 acres enclosed by the hoop.

There are 454 g in a lb. 454 x 0.00011 = 0.05

1 / 0.05 = 20. So you need to multiply the g/hoop by 20 to get lbs/acre.

Y x % Dry Weight = X

The % Dry Weight comes from this conversion chart. This is species-specific. So look up the plants you’re weighing. When we weighed, both the Brome and Alfalfa were in the pre-bloom stage which is 20-25% and 20% respectively. However, the field had just been irrigated and the plants were wet. So we chose to use a more conservative percent dry weight of 15%.

For example, for the first hoop we tossed on the conventional side of the field we measured 352 g alfalfa.

352 g x 20 = 7040

7040 x 0.15 = 1056 lb/ acre

We tossed the hoop again on the conventional side and repeated the above process to get a more representative sample, then repeated two tosses on the Biological side.

Our results:

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When assessing production by weight, the biological program seems to be at least competitive with the conventional fertility program, if not better! Keep in mind, these are the averages from only two tosses and results can vary. However as we walked through the fields with our local NRCS agent our visual observations were consistent with our hoop tosses. In our sample there was almost 50% more cache meadow brome on the biological side than the conventional side, and the alfalfa was almost equal on both sides. This is consistent with our observations from 2020 - the biology supported germination of brome and alfalfa over annual weeds, and left less ground bare than on the conventional side. These results are promising because they suggest the biological program can maintain production with lower inputs per acre without any chemicals polluting the watershed. One can choose to get ahead of the curve by applying additional biology, whether between cuttings and grazings, or in the fall. Then once the system is in balance, the inputs for the biological program decrease.

We will also count the bales from each side at cutting so we can get a more accurate comparison of production from each treatment program.

We learned a lot from this sampling method and recommend trying it out on your own place!