Enhancing Natural Soil Systems

 

Enhancing Natural Soil Systems

Peter Burton
19th June 2010


The concept that natural systems tend to wellness is for some difficult to understand and comprehend when so much of our work in any farming system is based on preventing illness and dealing with unwanted pest and disease.

Fear is a very strong emotion that drives much activity.  It seems that taking action to prevent something undesirable that may or may not occur is a stronger motivator than taking action to enhance desirable outcomes.

Fear of the consequence of not applying fertiliser drives a great deal of activity and expenditure.  Often when questioned closely farmers will offer the observation that they actually didn’t see a response to applied fertiliser or that there may even have been a suppression of growth immediately afterwards.

Perhaps this explains the continued purchase of nitrogen fertiliser; the initial response is often highly visual even though responses from subsequent dressings may become increasingly less. 

There is a real and immediate need for sound long-term trial work that incorporates all aspects of pasture performance.  During stated in the preface to Fertilisers and Soils in New Zealand Farming, “Field experiments measuring maintenance requirements of fertilisers and lime are extremely costly in time, land, and input of technical skill.  It is not glamorous research and it needs the co-operation of several disciplines for periods up to 15 years, and certainly an individual trial cannot be completed in less than 10 years.”

There is however a great deal of sound research when combined with good observation and common sense that provides the information necessary to sustain intensive and profitable pastoral production.

The quality of soil nearly always dictates both the quality and quantity of production.  Those that carved farms from bush knew that nearly always the areas where the bush was most luxuriant provided the most productive farmland.

With intensive livestock farming sometimes a trade takes place.  The more free draining ash soils of the Central Plateau due to both climate and natural fertility will grow less than the silt soils near river mouths, however the coarser soils allow for easier management as they are less damaged in periods of wet weather.

Damage by pugging restricts pasture growth in following months and the areas that suffer the greatest damage are slowest to recover and may not fully recover this season without remedial action.

Pugging or even heavy treading compacts soils reducing the pore space between particles and groups of particles, driving out oxygen and reducing beneficial biological activity.

One of the most important soil fungi is the mycorrhizal fungus.  Work undertaken by MAF in the 1970’s showed marked increases, particularly in clover growth, when mycorrhizal fungi were introduced into soils already populated with local mycorrhizal fungi.

These fungi infect the roots of clover as well as grasses, growing out from the root appreciably increasing phosphate uptake.  As clovers are less competitive than grasses for nutrient and sunlight the ability to stimulate clover by introducing highly efficient mycorrhizal fungi may significantly increase total pasture production. 
Doing as little soil damage as possible over winter and spring will in the first instance help ensure all beneficial soil dwellers are able to function efficiently maximising pasture production throughout the remainder of the season at little or no extra cost.

For more information, call 0800 843 809.