Comparisons between placing and broadcasting of nitrogen, phosphorus and potassium fertilizers for potatoes, peas, beans, kale and maize

Extract

1. In eight experiments on main-crop potatoes in 1953–4 placing 0·5 cwt. N/acre in a band beside the seed tended to give higher yields than broadcasting the dressing; when 1·0 cwt. N/acre was applied, broadcasting tended to be superior to placement. There were no consistent gains from placing 1·5 cwt. K₂O/acre.

2. Four other potato experiments in 1954–6 tested all combinations of placing and broadcasting two levels of nitrogen and potassium. There was no clear relationship between the effects of broadcasting or placing one nutrient and the way in which the other nutrient was applied. When 0·5 cwt. N was applied, placing gave higher yields in seven out of ten possible comparisons (one effect was significant). With 1·0 cwt. N/acre there were also seven of ten comparisons in favour of placement (three significant effects), but in two other comparisons broadcasting gave significantly higher yields. Placing potassium gave higher yields than broadcasting in sixteen out of twenty comparisons (six significant effects), in one of the remaining comparisons broadcasting potassium was significantly superior. Placing of the potassium and, to a lesser extent, the nitrogen components of a complete potato fertilizer is likely to be beneficial.

3. In two experiments each on green peas and broad beans placing of phosphorus and potassium separately and together gave consistently higher yields than broadcasting these nutrients. When nitrogen was used in addition to phosphorus and potassium there were small gains in yield of broad beans provided the mixture was placed. There were no gains in yields of green peas from nitrogen however the mixture was applied.