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.
Roots grow up to 5mm a day during the autumn, with up to 25mm in late spring, when growing conditions are at an optimum. The bulk of the nutrient uptake occurs in the top 30cm of the soil and an adequate phosphorous supply is vital for good root development.
Good soil conditions (dry soil) and early drilling generally facilitates good seedbed preparation. Early drilling allows for lower seed rates, seedbed rolling, reduced soil pest damage, efficient use of slurries and organic manures and root manipulation.
The evidence of early drilling and good growing conditions can be seen from the vigorous oilseed rape crops, and the effects of late drilling of rape is evident.
The majority of my clients established oilseed rape with min-till techniques and, as a consequence, there are high levels of cereal volunteers competing with crops, particularly along the old tramlines. The majority of these crops have been sprayed with robust rates of graminicides and, hopefully, this will do the job. Sterile brome, the constant weed threat in the min-till systems, is alive and well. This is particularly the case in some rape crops after winter barley, with the graminicide activity quite slow. The first of the winter barley crops are at the 1-2 leaf stage, with early sprayer excursions applying aphicide and herbicide.
Winter wheat plantings should be up this year, and hopefully the good start will pay dividends.
Gerry Bird is an agricultural consultant and member of the ITCA. Email: email@example.com