“We know we know so little about soil bacteria, but what we think we know might not even be correct” John Kempf.
Summary
John Kempf. An Amish community famer from Ohio, who has become one of the leaders in a science-focused approach to soil biology and nutrient management. He provides advisory services and supplies inputs through his business Advancing Eco Agriculture (AEA) https://www.advancingecoag.com He particularly focuses on fruit and vegetables.
The background to John Kempf’s approach is a very detailed understanding of soil and plant chemical and biological components and function. His main focus is on managing plant nutrient levels and enhancing soil biological activity to improve appropriate nutrient balance, availability and absorption. This is achieved by crop selection, green manuring and general use of biological additives such as mycorrhiza and highly specific fertilisers. He puts a strong emphasis on the use of sap analysis (as distinct from tissue analysis) as well as soil analysis to ensure optimum levels and balances as the principle means of managing crop nutrition and to guide the general application of macro and micro nutrients as soil or foliar fertilisers. He is using these techniques to manage pests and diseases as well as nutrient supply for crop yield.
Plant Sap Analysis was developed in The Netherlands and in its latest form is becoming more widely used, particularly for disease prevention and optimum nutrition for fruit and vegetable production. There are potential major advantages over tissue analysis; the analysis is very sensitive, it identifies the nutrients available to the plant’s cells, rather than total nutrients, some of which may be locked up, and it is possible to identify imbalances and disease susceptibility much earlier and before any symptoms are seen. For example manganese deficiency is a cause of powdery mildew, early identification allows time for foliar application before symptoms are seen. Used on a routine basis and to compare good and bad areas of a field the technique appears to be very useful for assessing the success of the crop rotation, manuring and fertilising practices to date and for deciding on the need for any soil or foliar inputs to the current crop.
Further information is available here http://crophealthlabs.com/wp-content/uploads/2014/09/ACRES.pdf
John Kempf introduces the technique here
https://docs.wixstatic.com/ugd/237db0_c5e14f9baf0d469d9bc8cc937cffca18.pdf
Sap Analysis is available in the UK from Omex http://www.omex.co.uk/agriculture/services/sap-analysis
This report which I have done on John’s conference presentation summarises the main points which he discussed; in this blog and my other Winston Churchill Fellowship blogs I have endeavoured to present what I have heard and not enter into a discussion drawing on my own experiences and ideas. In John Kempf’s ACRES USA presentation, as with others at the Conference, it is very striking how he focuses on detailed soil and plant analysis followed up with soil and plant soluble fertiliser and biological inputs. While this approach does make a major shift towards management of, and reliance on soil biology, rather than merely the chemistry, there is very little consideration of long term soil fertility, crop rotations, reliance on legumes for nitrogen fixation, maximising reliance on the soil for nutrients and the importance of soil structure. He advocates his approach for both organic and conventional farming, but it is undoubtedly a much more high input, short term approach than is typical of organic farming in the UK. The question remains: what is its potential for genuinely sustainable, biological farming systems?