Agriculture is a knowledge-intensive practice, and the current financial and economic turbulence means farmers must think carefully about how they invest and produce. Knowledge can help reduce the cost of inputs, and thus its importance today is greater than ever.
A question often asked is whether - and how - we can take advantage of existing soil fertility. At the field level, a soil test with data on crop response can supply the answer. On a larger scale, we often observe a large negative balance of nutrients, especially potassium. A negative balance of nutrients means that the removal of nutrients by harvest is greater than that applied in fertilizers, manures and crop residues. Typical values of negative balance for potassium can be in the order of 50 to 150 kg K2O/ha, or more, and can jeopardize soil fertility and impair productivity. Hence giving up today's nutrient application means limiting future yields - and income. There is also a need to look also at the efficient use of nutrients and water. Balanced fertilization with N, P, K, secondary nutrients and micro-nutrients will lead to better water use (and vice versa) and improve the efficient use of each nutrient.
There are no silver bullets in the field of plant nutrition: the products (fertilizers) of today are similar to those used 50 or even 100 years ago. So what, if anything, can be done differently today? Better soil and plant analysis, better placing of fertilizers in soil, appropriate application time - all these make plant nutrition, even with the same products used decades ago, much more efficient and productive. These days this simple understanding is essential.
In this edition of e-ifc we cover research on potassium nutrition in potato in India; nitrogen and potassium fertilization in poppy plants grown in the Czech Republic; and foliar spray of potassium on plums and peaches in Tunisia. All these papers reflect the experience of scientists striving to find better solutions for farmers.
