Focus on root development and early drilling for best 2011 crops
Published 12/10/2010 | 05:00
The past week saw plenty of activity in the fields, with drills working flat out to begin another cropping year. There is a good bit of optimism around, with a lot of growers availing of forward-selling contracts for next year, which is offering some market stability.
A good start is half the battle and this is particularly true where seedbeds are concerned. The basis of good yield is from the bottom up. The roots anchor a plant, feed it, source water, interact with beneficial soil organisms and are, essentially, the foundations. It is vital that your seed has a good germination percentage, good vigour, and low disease levels, especially fusarium spp.
Germination requires the correct combination of soil moisture, oxygen and temperature. But that is only the beginning of the story -- the plant has to grow.
Seed vigour dictates how quick the plant develops and is a factor of grain size (TGW), quality, seedborne disease levels, seed dressing (type, rate and coverage) and variety. The seed has a store of nutrients and is self-sufficient once germination takes place, until the first green leaves appear.
Producing the ideal seedbed has always been a challenge, as the range of equipment and cultivation techniques indicate. The fundamentals are the same. Sufficient moisture is needed to encourage germination, but not enough to drown the seed; there should be plenty of soil pore space to allow drainage, but hold sufficient moisture; enough air space, but not too loose; and the balance between air and water dictates the soil temperature. It is all simple.
Germination is generally the easy part -- just look at the growth of volunteers in stubble fields -- but it's the root development where the seedbed quality separates the good from the great crops. Roots grow from the tip, leaves grow from the base, so a fine, firm root-to-soil contact is vital along with the soil structure balance of air and moisture. The primary roots develop during the first month and are followed by the secondary roots after about two months.
The engine room is in place when lateral roots are produced, with a sideways spread capability of up to 1m, with metres of absorbing roots' hair surfaces. The bulk of the root mass is in the top 25-30cm of the soil, reaching a depth of around 0.5m by February, up to a metre by tillering, and up to 1.5-2m at full ear emergence.