Farm Ireland

Saturday 18 November 2017

Analyse soils for nutrient levels

Patrick J Phelan

Winter barley sowings should be completed as early as possible in October. Unlike wheat, barley cannot compensate for a low plant stand by increasing the size of the head.

Seeding rates and field germination are therefore critical in determining yield potential. The target seeding rate should be 300-350 seeds/m2, assuming field establishment of 85-90pc.

The Department of Agriculture's recommended list provides 1,000 grain weights for each of the varieties. Most varieties showed increased weights this year compared to the year before. However, there is considerable variation in seed size. This week I saw Saffron ranging from 52-61g (the Department's recommended list is 57.9g). In order to sow 350 seeds/m2, you would require 182kg/ha at 52g and 213kg/ha at 61g. For those who prefer to talk in terms of stone/ac, that is 11.5-13.5stone/ac.

Seeding rates should be increased if soil conditions are poor, sowing runs are late or indeed on land where you find it difficult to get and maintain tillers.

The six-row varieties, smaller seed, will generally require 20-30kg/ha less seed than two-row varieties. Hybrids may do well at lower plant stands than conventional varieties.

I have seen some severe slug damage in early sown winter rape, so it is obviously important to watch all sown crops and advisable to put monitoring baits in place before cultivations take place.


Application of chemical fertiliser, nitrogen and phosphorus, is prohibited from the middle of September to mid/late January.

Also Read

Statements of organic nitrogen and phosphorus production on farms for the period January to August were issued last week to most farmers. Those who are close to their limits will be looking for farmers to take slurry from them. This is an opportunity that should be taken up. You can spread organic fertiliser until mid-October, provided that there is a phosphorus requirement on your lands. However, the nitrogen and phosphorus content will reduce your chemical fertiliser allowance.

Soil sampling for organic matter is a requirement on all lands which are in tillage for six continuous years. You must have at least half of such lands on your entire holding sampled by the end of this year and the remainder will have to be done next year. The maximum sampling area is 8ha, provided that the lands are of uniform soil type and have a similar cropping history. Take the opportunity to analyse for lime, phosphorus and potash. Sampling might also be done for trace elements, if you have not done so in recent years, or on lands where yields are disappointing.

Home seed

Home-saved seed offers scope for savings but is very expensive if it goes wrong. If you decide to do so, seed should be tested for both germination and seed-borne diseases. Loose smut was evident in some crops this year and results of recent samples have shown high levels of fusarium in some lots.

Home-saved seed should only be used if you are sure that it is not contaminated with weed seeds or wild oats. Royalties must also be paid.

Patrick J Phelan is an agricultural consultant in Co Tipperary and a member of the ITCA. Email:

Irish Independent