This article will refer to narrow row cotton only as that currently being grown in 75 cm rows (30"). The older system of high density stripper cotton will not be discussed.The great theoretical advantage of narrow rows is to reduce early season competition between plants, giving potential earliness and yield advantages. This is achieved by maintaining the same sowing rate while decreasing row space. All results of high density and narrow row experiments show clearly that plant competition at the squaring and flowering phases reduce fruit retention and boll size, particularly of early bolls. The theoretical yield and maturity advantages of narrow rows depend on good retention of lower fruit.

Nitrogen management plays a key role in cotton production. It is the nutrient required in greatest quantity by the crop and it is the nutrient most often deficient. Despite a large investment in fertilizer N in cotton cropping systems, the efficiency with which it is used by the crop can often be very low. This efficiency can vary greatly from season to season, between different forms of management and between cotton cropping systems. Much of this variation can be attributed to variations in the amount of N lost from the cotton cropping system.

This project was established to find a simple, repeatable and reliable technique or series of techniques for consultants, extension personnel and managers to use to assess soil structural conditions in the field. These techniques are also being related to the more precise teclmiques that are used by research persormel. All of these techniques, both advisory and research, are being related to cotton root growth and yield.

Cotton growers began to realise in the late 1970's that compaction of clay soils may have been a cause of declining yields. Research over the last 10 years has confirmed those suspicions. Compaction can be a widespread and severe limitation to yield; it can also be avoided or repaired . Research findings are of little use on their own. Users must be convinced of the magnitude of the problem and be given ready access to information which can help them overcome a problem. The SOILpak project set out to address these issues by promoting the importance of good soil management, by drawing together existing research results and practical experience, and by presenting the knowledge in a decision-support system. A loose-leaf manual was the medium chosen to deliver the decision support system. This medium makes the information easily accessible, especially in the field where many management decisions are made.

The companion project to SOILpak, "Soil management training for advisers to cotton growers" has made a good start in familiarising consultants and agronomists with structural recognition. The series of soils workshops for consultants and agronomists that started in 1990 in the Macquarie Valley (Abbot 1990) is now complete following the running of the Central Queensland workshop at Emerald in May 1992.

We have conducted a series of experiments at Trangie, Warren, Narrabri and Moree to examine the use of shallow leading tines in conjunction with rippers. Ripper depths of 300, 450 and 600 mm have been investigated. Several leading tine configurations were used at depths of 150 and 300 mm. The leading tine configurations were based on chisel plough tines fitted with chisel points and sweeps. Soil disrurbance and the forces on the tines were measured. Soil disrurbance was greater when leading tines were used. Some leading tine configurations reduced the total draft in some cases while other configurations increased draft. Ripper depth was the most imponant factor in detennining total draft. The use of shallow leading tines allowed more soil to be loosened with reduced ripper depth and draft.

Obviously, avoiding trafficking wet soil is one means of avoiding soil structural damage. Another is to use a vehicle with lower ground pressure, by using dual tyres, wide tracks, etc. But which is more important - soil moisture or vehicle ground pressure? What are the trade offs? This article seeks to explore these questions.

Retained hills are now a well-established management strategy in the Australian Cotton Industry. They provide the Industry with a unique strategy to control soil compaction, ensure long-term maintenance of the soil resource, and provide lower cost land preparation. Growers should be aware, however, of several potential management problems inherent in the system, especially as approximately 80% of irrigated cotton is now grown in retained hills. There are two potential problems: keeping compaction out of retained hills, and ensuring wheel compaction is removed if hills need replacing. The frrst part of the paper will address this. The answer to both lies in a working knowledge of wetting/drying cycles, that is the process that controls structure formation in most cotton soils. The second part of the paper will address this.

This paper provides an overview of the Cotton Research and Development Corporation project DDI lL, which is in its final year at the University of Southern Queensland. The main aim of the project is to develop a suitable management system for cotton growers that will minimize tillage requirements and avoid current problems with soil compaction caused by heavy machinery. The project is based on a controlled traffic approach that maintains compacted lanes for machinery and a compaction free plant environment

Numerous alternative control techniques have been available In various forms for many years. Unfortunately none of these alternatives have been regarded as practically or economically viable. Obviously such a statement results from a comparison of these alternatives to the extremely effective, quick and cheap control provided by lnsecticid.es. Now that the resistance situation is beginning to develop further and the acceptance of insecticide use is being questioned, the comparison between insecticides and the alternative techniques becomes much closer.