Directors Dr Peter Bishop and Dr Bert F. Quin
Introduction
Differing local soil, climatic and environmental limitations both throughout the world and within individual countries can greatly affect potential production
The mission of Advanced Agricultural Additives Ltd is to study these limitations, and develop targeted solutions to those limitations which are particularly relevant to fertiliser nutrient efficiency, nutrient cycling, and nutrient loss to the environment.
Since its inception in 2011, AAA Ltd has already researched, developed and brought to market two very significant products, AlpHa® and ÒRUN®.
Products
AlpHa®
AlpHa® is a synthetic carboxylate polymer of fulvic acid, designed to maximise the potential of soil organic matter by complexing soluble, positively charged metal ions in the soil solution. Positively charged ions of aluminium (Al), manganese (Mn) and iron (Fe) can produce phyto-toxic effects in pasture and crops, which reduces yield and limits the uptake and utilisation of plant nutrients.
Research with AlpHa®
When tested for effect against finely ground limestone (lime flour, LF) in pot trials, AlpHa® applied at 2 l/ha produced growth rates higher than 100 times as much LF (Bishop & Quin, 2012) , as shown below-
Figure 1 Cumulative dry matter response of ryegrass (Moata) to lime flour applications of 0, 50, 100, 200, 500 and 1000 kg/ha and AlpHa® at 2l/ha. Acid soil with an initial pH 4.8 (Bishop et al. 2012).
The ability of AlpHa® to specifically reduce metal toxicity in ryegrass (Moata) was demonstrated in solution culture studies (Bishop, Jeyakumar & Quin, 2013). Shoot and root growth was measured over a 6 week period. The test solutions used concentrations of Al from 0 to 1.6 mg/l, Mn from 0.05 to 40 mg/l, and Fe from 1 to 80 mg/l. AlpHa® concentrations used were 0, 0.2, 2 and 20 μl/l or l/ha.
At levels greater than 0.2 μl/l in the growth solution, AlpHa® prevented shoot growth suppression of Al up to a concentration of 1.6 mg Al/l, and reduced the effects on root growth suppression. The toxic effect of both Mn and Fe on grass growth was reduced by AlpHa® to up to 2μl/l Mn, and up to 0.2 μl/l for root growth in Fe.
Figure 2 Growth response curves for herbage and roots of annual ryegrass (Moata) grown in nutrient solutions containing added Al, Mn and Fe, with AlpHa® added at 0, 0.2(■), 2.0 (▲) and 20 μl/l (♦). Lines show the fitted herbicide dose response for each metal and AlpHa® combination.
These published results provide the scientific evidence that AlpHa® has the ability to reduce limestone application rates and reduce Al toxicity on pasture production in acid soils.
Additional benefits of applying AlpHa® with fertilisers
When applied with phosphate fertiliser, AlpHa® can also influence the effectiveness of the phosphate in a similar manner to limestone, by reducing Al toxicity and increasing growth response (unpublished). The preliminary results of coating granular diammonium phosphate (DAP) with 2l/tonne of AlpHa® showed an increase in herbage growth response by over 100% compared to the uncoated DAP, when applied to acid high P fixing soils. Similar results have been obtained in field trials.
Figure 3 Cumulative herbage growth of ryegrass (Moata) grown in acid Dannevirke silt loam (pH 4.3) in response to the addition of DAP (20 kgP/ha) coated with AlpHa®, Calcium lignosulphonate (Cal-lig), wattle extract tannin (Clarotan®) and slow release polyurethane (SRLPDAP) at rates equivalent to 2l/tonne and 5% in the case of SRLPDAP. The Nil-P control using sulphate of ammonium as N source. Grass was cut at 26 and 49 days.
The results of these trials have demonstrated that AlpHa® is an effective product for controlling the effects of Al toxicity in pasture reducing the amount of limestone required and enhancing the effects of added fertilisers on pasture growth limited by phytotoxicity.
Bibliography
Bishop, P., Quin, B., Pham, T. S., & Nguyen, L. (2012). The use of poly-carboxylic acids and sodium silicate to increase fertilizer P efficiency and reduce lime requirements on acid soils in New Zealand and Vietnam. In: Advanced Nutrient Management: Gains from the Past – Goals for the Future. (Eds L.D. Currie and C L. Christensen). http://flrc.massey.ac.nz/publications.html. Occasional Report No. 25. Fertilizer and Lime Research Centre, Massey University, Palmerston North, New Zealand.
Bishop, P., Jeyakumar, P., & Quin, B. (2013). Amelioration of Al, Mn and Fe toxicity in ryegrass clover, and wheat and rice, by poly-carboxylic acids. In: Accurate and efficient use of nutrients on farms. (Eds L.D. Currie and C L. Christensen). http://flrc.massey.ac.nz/publications.html. Occasional Report No. 26. Fertilizer and Lime Research Centre, Massey University, Palmerston North, New Zealand.
A typical dairy grazed pasture, showing massively higher growth from urine patches. This is partly because stock avoid grazing the most recent ones until all other grass is eaten, but more important is the high content of N, other nutrients, and rapidly mineralised organic matter.
ÒRUN®
ÒRUN® is a patented combination of products, individually all already widely used, and proven completely environmentally safe, in agricultural systems. It was developed specifically for the treatment of cow urine patches, to optimise plant recovery of the urine N from the soil, and in so doing greatly reduce nitrate-nitrogen leaching and gaseous GHG emissions.
ÒRUN®–A comprises a base of two products, viz the urease inhibitor n-(N)-butyl-thiophosphoric-triamide (NBPT) and the growth promotant gibberellic acid (GA3). In appropriate soil conditions, where dissolved organic carbon (DOC) may be limiting, the poly-fulvic polymer AlpHa® is included in ÒRUN®-B.
Trial results are available on the Pastoral Robotics page.
