The evaluation of EMNZ Microbial products on the yield and composition of irrigated pasture
Field Report (2021/2022)
Trial aim:
To evaluate the effect that a range of EMNZ Microbial products has on irrigated Canterbury pastures and how they compare to traditional Nitrogen (urea) applications.
Three aspect of pasture performance was evaluated:
Dry matter yield (kgDM/ha)
- Clover content within the pasture sward
- Root mass of the pasture
Results
Dry matter Yield (kgDM/ha) Similar trends were seen across all harvest dates, with the high rate of Urea (80 kg/ha) consistently producing the highest yield. While the yield was not always significantly greater than the other treatments, it consistently produced the highest yield (Table 1). EM Soil & Crop + urea (40) and EM Plant Stimulant + urea (40), also produced consistently high results across all harvests compared to other treatments. EM Plant Stimulant + urea (40) and Urea Full (80) are the only two treatments that had significantly greater yield than the control at every single harvest. When looking at the combined total dry matter yield grown over the entire trial period (Table 2), all treatments except EM Soil & Crop (20) grew significantly more total yield than Control. Urea Full (80) grew the highest amount of dry matter, but this was significantly similar to that grown by EM Soil & Crop + urea (40), EM Plant Stimulant + urea (40), and EM Fert Enhance + urea (40). The addition of EM Soil & Crop, EM Plant Stimulant, and EM Fert Enhance to urea (40) significantly increased total dry matter production compared to urea (40) alone or the EM products alone. This indicates these products are enhanced when small amounts of nitrogen are added to them.
Clover Content
There were some clear treatment effects on Clover Content within the pasture sward. As expected, the high rate of urea (80) reduced clover content at both assessment dates. This is often seen in high nitrogen use systems. The low nitrogen rate (urea 40) had no effect on clover content (Table 3). At the first assessment date, EM Soil and Crop and EM Plant Stimulant significantly increased clover content compared to untreated control and compared to both urea alone treatments. At the second assessment date a similar result was seen, although EM Plant Stimulant had similar clover content to untreated. At the first assessment date, EM Fert Enhance did increase clover content compared to untreated, but this was not statistically significant. It did however significantly increase clover content compared to the urea only treatments. A similar result was seen at the second assessment date, but the increased clover content was seen only against the high rate of urea. The addition of 40kg/ha Urea to the three EM products did reduce clover content but not statistically.
Conclusion
All three EM products showed that they have a positive effect on pasture production. While on their own the level of dry matter production was lower than that of high rates of nitrogen, in combination with lower rates of nitrogen they provide significant benefits. The total dry matter produced by combining each of the three EM products with 40kg urea/ha, was equivalent to that grown by applying 80kg urea/ha. This means that farmers can reduce their nitrogen inputs, but can grow equivalent amounts of pasture by adding in one of the EM products. This has significant production, economic and environmental benefits. The increased level of clover being able to be produced by implementing the above system, compared to high nitrogen systems, will also be a long-term benefit for pastoral farmers.
