WHAT’S YOUR COLOUR?
With three trade shows coming in quick succession this year, LAMMA, Cereals and Groundswell, the question of which colour you like your steel painted comes into focus once again. Written by James Warne from Soil First Farming Along with the rise of the Conservation and the structure soil no longer has Magnesium can hold onto 18 Agriculture techniques being adopted the porosity for air and water to move molecules of water when fully hydrated. on more and more farms across the freely within it. In our maritime climate Magnesium also has a relatively large UK, the choice of zero-till drills seems there are times when our soils have to charge density compared to other to grow day-by-day. Significant cope with prolonged periods of excess common soil elements like calcium government support incentives also water. A lot of focus is put into sorting so water has a greater attraction to has an involvement in driving this out failing drainage systems. While magnesium. This tends to keep soils growth, but without the most sensible this is important, if the soil porosity is wetter and then dry rapidly, giving outcomes. Machinery manufacturers not connected to the drains its largely greater shrinkage when it finally dries. This shows when the slots open as the are showing their ability to design ever irrelevant. more sophisticated machines, mostly Too often we see soils which have soil surface dries as mentioned above. based around a disc style opener. slumped due to low organic matter, and It can also help with structure and Machines are becoming every larger excess water, being late drilled with a porosity improving water movement and heavier and demand a greater disc drill. More often than not these and infiltration. Understanding how draft requirement. Very few tine- crops tend to come through the winter the magnesium and calcium balance opener machines are available and are low in plant numbers and are unable is affecting your soil can lead to better clearly not in favour, which needs to be to tiller adequately to compensate, decision making around drilling and addressed in our opinion. resulting in thin crops now being visible. crop establishment. As usual at this time of year, with Narrow knife style tine openers tend wheat now full in ear across the country, to operate better in the early years of the variation in crop establishment can zero-till on low OM soils. Tines will now be seen. Consistent with the last create a little tilth to improve seed few years a lot of thin zero-tilled crops to soil contact, whereas discs do not are evident. The push for later and create any tilth. When the soil is moist later drilling exacerbating this effect. a disc will actually smear the seed slot This is the disc drill fallacy. it creates further reducing drainage and restricting crop rooting. Seed slots created by disc drills in wet conditions may appear closed at the time of drilling but will open again as the soil dries in the spring exposing the root crown to the air. With second cereals disc drills can also be problematic when drilling into Typical slot opening in spring on moderate magnesium soil chopped straw. Do not underestimate the effects of hair-pinning on the In our opinion a tine drill is critical subsequent crop. Thin or small-eared for success in the early years of zerosecond cereals seen now could be a till. Simple, uncomplicated, low draft result of the actions taken at drilling. requirement tine drills can have a very It may not be the fault of a firm soil big impact on the success of zero-till Typical disc drilled thin wheat crop or lack of moisture or nutrition, it may adoption in the UK. The choice of disc simple by the wrong choice of drill for versus tine drill at the point of drilling With many soils in the UK now the situation. is a critical control point many growers very low in organic matter it has lost Overcoming chemical imbalances are overlooking. Simple tine drills the glue which binds it together. Low within the soil can also help alleviate give great opportunities and low draft organic matter soil has generally has the effects of a soil with poor structure. requirements even with large output poor structure, and tends to slump The water retaining properties of potential. and compact easily. Without the glue magnesium are well understood. 8 DIRECT DRILLER MAGAZINE
ISSUE 18 | JULY 2022
