Geoscience Reference
In-Depth Information
This conclusion was based on a survey of 70 organic farms and 40 conventional ones
by a research team from the Department of Economics, University College of Wales
at Bangor. Although the majority of organic farmers had lower financial returns, some
outperformed the conventional average. Furthermore, organically grown produce can
command a higher premium which can shift poor returns to good ones. This higher
premium depends, of course, on a favourable supply:demand factor; if more farmers
entered this market the premiums would be reduced.
No one questions the value of organic matter in the soil for making cultivations
easier and improving seed beds. However, organic farming by itself does not increase
soil organic matter unless very large quantities of farmyard manure are used, or a sys-
tem of ley/arable farming is adopted. Measurements made by the Agricultural Devel-
opment and Advisory Service at the Soil Association's farm at Haughley, Suffolk, did
not show extra total soil organic matter compared with adjacent fields receiving con-
ventional fertilizers and management.
As a source of major nutrients, the main difference between manures and inor-
ganic fertilizers is in the slower rate at which nitrate-N is made available to crops.
This may be an advantage as less may be lost by leaching, as shown in the Broad-
balk experiment described earlier. Because of its high water content, however, ma-
nures cost more to transport and spread: the NPK in a tonne of farmyard manure can
be matched by 37 kg of fertilizer, 1/27th the weight. On a national scale, there would
also be a very real problem of retrieving and recycling the nutrients carried from the
farms into the cities. This would be extremely expensive but the time may come when
society will have to consider seriously the pollution and waste of resources entailed
in the present policy of sewage disposal.
In practice, it is difficult to draw a clear line between organic husbandry and con-
ventional farming. It is an attitude of mind as much as anything. Some would consider
it a test of man's stewardship of the Earth. An American survey showed that farms run
on organic lines were also most energy conscious and employed methods designed to
minimize water pollution and soil erosion.
We have yet to see whether British farmers will reduce their use of agrochemic-
als on crops in response to pressures to reduce productivity, or will maintain intensive
use on reduced areas. The Set-Aside scheme does not allow grass strips around ar-
able fields to be used by livestock, so there is no encouragement for a return to more
mixed farming.
