The objective of the experiments reported in this paper is to determine the fate of fertilizer nitrogen applied to the grey clays in the Namoi Valley.

In dealing with nitrogen and Pix, points to put the issues in context are that nitrogen is the most important because it can increase yield by much more than a growth regulator such as Pix can. However the two inputs interact because with nitrogen deficiency, Pix may decrease yield. My research aims to combine agronomic inputs so that we can manage cotton to improve efficiency or productivity in a sustainable way. The environmental ledger associated with nitrogen fertilizer use is a maintenance of soil fertility but potentially greater nitrate in the ground water and more nitrous oxide emission to air.

Rainfed cotton has been grown in Central Queensland since the 1920's but the total area has fluctuated in response to variable seasonal conditions as well as changing prices and market trends for cropping options.

The wild ancestors of cotton are found in the arid regions of the world. They are adapted to survive long periods of extremely dry weather and to respond to an occasional storm or flash flood by rapidly producing fruit while conditions are favourable. Modem cultivated cottons have inherited these attributes, making the crop uniquely adapted for both rain-fed and irrigated production. In Australia cotton was grown for over 100 years as a rain-fed crop before the introduction of the intensive irrigated technology. Rain-fed production is undergoing a renaissance prompted by a high cotton price and low grain prices resulting in the emergence of a new technology derived from a marriage of modem broadacre grain production and irrigated cotton production.

Very few economists are employed in Australian cotton research. Biological researchers often seem to believe that the job of economists is just to "put in the prices" after a new technology has been developed. Certainly, there is confusion amongst scientists about just what an economist does do, or can do. In this paper, I want to outline some of the areas where an expanded economic input into the Australian cotton research programme might be justified. This can be done under three headings: project selection/portfolio management; economic optimisation; technology design and research management.

Selection of the area of irrigated cotton to plant is a perennial problem. Research by the Centre for Water Policy Research (1989) has shown that growers solve this on the basis of their total water allocation and expectations about the price of cotton. Hearn (1988) has shown how the yield of cotton changes in different years with different field allocations of irrigation water, using a cotton water balance model. However, this analysis is in tabular form and difficult to customise to suit individual situations with different land area, water supply, irrigation efficiency, soil water deficit for irrigation, maximum yield, cotton price and variable costs. In this paper, we show how a lookup table of the kind provided by Hearn can be re-formulated as a spreadsheet template in order to simplify the analysis of the underlying lookup table and provide a tool for decision support.

Many cotton growers are asking Why can't Australian cotton mills spin more cotton?" Many hundreds of thousands of bales of cotton are imported into Australia as finished yarns and fabrics - why can't this be Australian cotton through Australian mills? In addition to the domestic market, why can't Australian mills export their product as Australian farmers do

As most cotton is exported the cotton industry has a high exposure to exchange rate fluctuations. Similarly, as credit is such an important part of the cotton enterprise interest rates are an important cost factor.

The past season has been 11 abnormal 11 - how do we define a 11 normal" one? - but abnormal in the sense that significant shifts in trading patterns have occurred. Most striking has been the setback to the Soviet 1989/ 90 crop, hard hit by frost at planting time, together with Pakistan's huge expansion of domestic spindleage. Neither country, therefore, could be looked to for its customary export supply. India's emergence as a considerable provider to world markets was thus fortunate since her medium and short staples proved idea 1 rep 1 a cements for the missing Pakistan styles. And China, the most unpredictable of all, continued to buy