Gordon Rajendram the soil scientist

April 2023

New Zealand’s leading expert in soil fertility, Hamilton-based Soil Scientist Gordon Rajendram (PhD) looks at ways of increasing a farm’s profitability in times of recession

The most economical forage for animals is good nutritious pasture which includes good energy, protein that is digestible and has fibre in it. The cost to produce pasture can cost between 2 – 6 cents per kilo of dry matter. In order to achieve the above, you need to have adequate nutrients in the soil. Farm’s profitability starts in the soil and getting this right will, without doubt, lead to great pasture and better soil health, i.e., it is aerated, it holds onto the nutrients, whatever is applied doesn’t leach and the right forage types. Having a variety of species of forage is beneficial i.e., grass, clover, herbs etc. The importance of independent soil management and fertiliser advice is crucial rather than just someone trying to sell a product. There appears to be major conflicts of interest in this area. Large savings can be made if the advice is correct. The 16 elements are required for pasture and animal health. In some cases, excess money is spent on elements that are not necessary and hence the importance of independent advice. Soil management is an expert area and one which can lead to better profits. Sampling is one of the crucial aspects of soil management. Soil is important at the start and pastures grown on this are essential for farm profitability.  New Zealand is the best at converting pasture to milk and protein (meat) but there are still ways this can be improved. New Zealand farmers have the lowest carbon footprint to produce meat and milk Published research shows that NZ farmer’s carbon footprint to produce meat and milk is the lowest compared to other countries. In the dairy sector, the emissions to produce 1 litre of milk have been estimated to be 0.9 kg CO2 when compared to the global average of 2.4 kg CO2 per litre of milk. In the NZ dairy sector, PKE was the main supplementary feed type used on farms. PKE though has the highest carbon footprint of any brought-in supplementary feeds. NZ’s carbon footprint to produce beef is one of the lowest with ~9 kgCO2e/kg LW and NZ’s carbon footprint to produce sheep is the lowest at ~6 kgCO2e/kg LW.  This is due to the NZ lower cost pasture grazed-based systems. Compare this to say in many parts of the world where pasture or crops are cut and carried and fed in a shed system. Studies have shown for humans to have a balanced diet a component of milk and meat is required. A lot is going on below the ground (leaching) so this has to be prevented and lead to greater profits. Accurate testing is essential to ensure more efficient ways of nutrient uptake. There must be nothing limiting this process in the soil. Whatever is applied you must make sure the soil can hold onto this and that it is not leached. Having a whole lot of fertiliser on top is only part of the process. Having knowledge of what is going on underneath the ground is critical to profitability. Contact Gordon: Email: rajendram@xtra.co.nz Facebook: https://www.facebook.com/Gordon-Rajendram-Soil-Scientist-830978353759572/ Contact MediaPA: Phone: 0274 587 724 Email: phillip@mediapa.co.nz Website: www.mediapa.co.nz Facebook: www.facebook.com/MediaPA Twitter: twitter.com/NZ_MediaPA YouTube: www.youtube.com/user/TheMediaPA Pinterest: www.pinterest.com/NZMediaPA

New Zealand’s leading expert in soil fertility, Hamilton-based Soil Scientist Gordon Rajendram (PhD) looks at ways of increasing a farm’s profitability in times of recession Read More »

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Hamilton-based Soil Scientist Gordon Rajendram recently visited An efficient dairy farming system – Ngatimaru Farms – and these are his findings.

The farm and production: I consult to dairy farmers Rick and Dianna Bourke whose farm is inEiffelton, 15 minutes away from Ashburton. The farm is approximately 10 km from the Canterbury East Coast.They have a Jersey herd of 740 cows, with cow weights on average being 425 kg. The cows dietconsists mainly of pasture with in shed feed of 2 kg of a blend/cow/day and the farm is irrigated.The average farm milk production over the past three years has been 350,000 MS/year with theaverage cow production being 480 MS/cow. If you don’t test you cannot manage: The farm was comprehensively soil tested (called soilbenchmarking a farm) to determine the nutrient and soil pH status of the farms in winter of 2020when cows were wintered off. Tests included anion storage capacity (ASC), cation storage capacity (CEC), Olsen P, resin P, Sulphate-S; exchangeable calcium, magnesium, potassium and sodium; TP, TS, TN, TC, organic matter, and trace elements boron, copper, zinc, cobalt, selenium and molybdenum.Through a comprehensive testing and data analysis, paddocks were identified that were belowoptimum, at optimum or above optimum for each nutrient. From this nutrient density maps were created for each nutrient or soil parameter. The results from the testing showed that the soil on the farm had low Phosphate retention (ASC) and Sulphur retention ability.Pasture and clover only was determined for its nutrient content in spring and autumn when the pasture is actively growing. Pasture growth rates and pasture covers on the farm are measured weekly by GrassCo. Minimal N and Fertiliser use:The nitrogen applied on the farm over the last 3 years has been on average 74 kg N/ha/year, applied via foliar spray using a 6200 L AMAZONE spray unit. Other elements and trace elements that can be solubilised are applied with the foliar nitrogen as required based on soil and pasture testing. Lime was applied to achieve a soil pH of ~ 6.4Phosphate applied to paddocks as RPR or Di-calcic if Olsen P <20 and P withheld if Olsen P >30.Sulphur applied at 30 kg/ha using elemental S to all paddocks.The soils were very compacted. One of the reasons for the compacted soils is because of thenaturally high magnesium levels. To help fix the compaction issue and aerate the soil, theAgraforum soil conditioning program was used. Forage with multi species:Multi species (~ 9 – 11 species) was grown on a few paddocks and compared to rye grass/cloverpaddocks. A root enhancing product was applied to improve root growth. Outcomes from the visit as summarised:Duncan Barr, is measuring the grass growth using GrassCo technology on the farm, commented: “It is very noticeable how good, even and dense the pasture growth is compared to other farms”. “It’s as if they are using 300 kg/ha/year of nitrogen when they are actually using much less”.This farm has low, but efficient use of fertiliser and nitrogen to produce quality pasture, and consequently the cost to produce milk is very low.Cows produce extra 1 Litre of Milk when cows graze on multi species paddock compared to when grazed on just ryegrass clover paddocks.This is an extra 0.1 kg of milk per cow which equates to ~$0.90/cow/day. So, for the 740-cow herd it is an extra income of ~$660 per day when the multi species is grazed. The plan now is to put more paddocks into multi species.

Hamilton-based Soil Scientist Gordon Rajendram recently visited An efficient dairy farming system – Ngatimaru Farms – and these are his findings. Read More »

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