Collaborating Producer: Grant and Audry Gaschnitz, High Prairie
Research Coordinator: Dr. Akim Omokanye
Calcium (Ca), in various forms, has long been the go to mineral when adjusting for pH, but it also performs other functions in the soil and plants. It is the tour guide and referee to nutrients in the soil, as it can lower the conductivity of the soil, and with a lower conductivity, minerals that were previously locked up are now available for the plant’s use. Genesis Soil Rite (GSR) Ca from Sustainable Soil Solutions (http:// www.ssscinc.com/gsr.html) is a proprietary blend of lime, limestone and all natural minerals, herbs and spices for the soil. The term “Compost Tea” specifically describes the watery solution obtained by soaking compost in water in the presence of nutrients such as molasses, kelp, humic acid and fresh fish fertilizer. Compost tea (CT) is a readily available form of compost that will affect the plant more quickly than compost mixed with soil. Different types of compost can be used to create the tea depending on what factors you would like to affect in your soil, such as better fungal growth or bacterial or both. The following report highlights the results of a trial on the assessment of forage yield and quality following GSR Ca and compost tea applications.
The trial commenced in 2010 on a declining pasture located in High Prairie. The pre-inoculation of compost (compost activation) should begin 5 days before brewing and this involves measuring a predetermined amount of compost ingredients (Alaska humus, worm castings, humic acid, fish fertilizer, oat flour), mixed thoroughly and allowed to stay for 5 days. The brewing (tea making) process involves placing the active compost into a large water permeable teabag (800um) along with an aerator stone. This is placed into a 650L non-chlorinated water filled tank and some more additives such as humic acid, kelpgrow and fish fertilizer added for microbes to feed on. Another aerator stone is placed inside the water tank for ample aeration. The brew is aerated for 24 hours before application. The water to be used would have to be put in the tank 24 hours before brewing to bring the temperature of water up to air temperature. The brew time allows time for the water to become inundated with fine particulate matter, microbes and soluble chemical components of compost. Well oxygenated water at the correct temperature allows for the living organisms and nutrients in the compost to migrate to the water and become active.
In our study, we imposed three treatments and these consisted of: (1) application of GSR Ca alone, (2) application of GSR Ca + Compost Tea (CT), (3) application of CT alone, and (4) check plots. Both the GSR Ca and CT were sprayed into the desired treatment plots. Each plot measured 2 acres. The goal with the GSR Ca and CT was to create better soils, both in structure and in microbial activity, as well as healthier plants, by increasing protein and improving forage digestibility. Following 24 hours of brewing, the tea is transferred into a sprayer. The tea is then sprayed (foliar sprays) into the desired treatments (GSR Ca + CT and CT) at 50 L/ac. A boomless sprayer nozzle is used so that the brew is not forced through a small space and this also prevents clogging of sprayer nozzles. The whole process of compost activation and brewing was repeated two more times and sprayed into the desired treatments. We sprayed the tea in the spring, summer & fall of 2011. More information on compost tea ingredients, activation, brewing and application process can be found in PCBFA Annual Report 2010, ARECA website (www.areca/members/Pcbfa.html) and Peace River Forage Association of B.C. (http:// www.peaceforage.bc.ca/). Grazing cages were randomly placed in each paddock and the forage within each cage was cut to enable DM yield estimation. Forage was cut on June 22 and August 26, 2011.
Forage Yield and Quality
When cut in June, forage DM yield increases of treatments with GSR Ca alone, CT + GSR Ca and CT alone over the check plot were respectively 15, 131 and 107% (Figure 1). August cut produced lower yield differences– 106% for GSR Ca alone, 116% for CT +GSR Ca and 99% for CT alone. Total forage DM yield (June + August cuts) increases were 110, 123 and 102% respectively GSR Ca alone, CT + GSR Ca and CT alone over the check plot. Generally, there was no significant improvement in forage DM following GSR Ca and CT applications.
Table 1 shows protein, Ca and P contents of forages harvested in June and August. There was no clear pattern in forage protein and P contents irrespective of treatments imposed. However, with regards to Ca content, application of GSR Ca alone or in combination with CT seemed to have favored higher Ca contents of forages harvested at both dates (June & August). Compared to both check and CT alone treatments, forage Ca contents of plots with GSR Ca alone and CT + GSR Ca met and even far exceeded Ca requirements of for all classes of beef cattle. ADF, NDF and TDN were all very similar for all the treatments (data not shown).
Compost tea is not designed as a quick fix solution and several applications a year for some years may be needed to bring the microbial biomass back to where it should be. Then the microbes can often release nutrients bound in the soil making them more readily available to plants and the soils will have better decomposition of organic matter and soil structure, making nutrients more available to the plant thus giving greater forage productivity. Next spring we will complete a soil biology test to see if any improvement have been made to the soil microbes.