Energy requirements of inputs to agriculture in New Zealand

Abstract

As New Zealand's agricultural production has become more mechanised and dependent on inputs of fertilizer and pesticides, it has become increasingly dependent on imported fossil fuels, which are rapidly diminishing in supply. New Zealand's imports of fossil fuels are likely to become subject to interruptions or reductions in supply and to rises in cost. There is therefore a growing need to understand the nature of the energy requirements of New Zealand's agriculture. The effect of price rises or shortages of imported fuels may then be assessed, different farming methods compared or plans formulated to maintain productivity as the supply of imported fuels becomes restricted.

The objective of this project was to produce a list of energy requirements for the inputs of materials and equipment to agriculture in New Zealand, and to use these energy requirements in a practical situation to determine the total energy requirement of a specific agricultural product.

The discipline of energy analysis has been developed recently to determine the total energy requirements of processes or products. The method of energy analysis used in this project is process analysis, by which the total energy requirement of a commodity can be calculated by tracing all the energy inputs to the network of processing and transport stages from the raw material to the finished product.

The total energy requirements for the following inputs to New Zealand's agriculture have been determined using a process analysis: fertilizers, structural materials, farm machinery and implements, fencing materials, pesticides, irrigation and water supply and seed dressing. These energy requirements have been used to calculate the total energy needed to grow sugar beet in Mid-Canterbury.

The calculation of the energy requirements for New Zealand agriculture was a laborious and time-consuming process with many inherent inaccuracies and difficulties, such that complete, precise determination of the energy requirements was not possible. If energy analysis is to become a valuable input to decision-making regarding New Zealand's agriculture a more reliable and comprehensive collection of energy requirements needs to be determined.

Despite the difficulties involved, energy analysis could be developed in New Zealand and used to advantage alongside economic and environmental assessments.