Mechanised farming has bought many benefits to Asian agriculture, allowing previously unworkable land to come into useful production for its owners. This has allowed the sugar industry as we know it today to develop and provide a significant contribution to the economy. However, we are finding now that like many other of man’s interventions on the World’s environment it needs to be managed. Diminishing return from previously productive land has started to become an issue and this is most noticeable when water becomes scarce and the general crop tonnage is reduced as in our last “crushing season”. Unfortunately, one major influencing factor is the use of inappropriate mechanisation.
Vehicles that exert excessive point loadings on the land cause soil compaction, eventually creating an impermeable crust on the surface of the fields. As it is a perennial grass, sugarcane, (Saccharum officinarum), like other grasses will respond well to cutting. So with a good supply of nutrient and moisture to its relatively shallow root system, it will continue to grow even after severe pruning. We enjoy this phenomenon as our “ratoon” cane and this facet of reproduction is factored into the economical calculation of virtually every cane farmer worldwide. However, reliable “ratoon” is becoming a thing of the past as compacted soil produces less usable product year on year. The soil simply does not have the capacity to support viable plants once it has become severely compacted over a period of time by tractor, harvester and carry truck traffic.
Rehabilitation of inert fields can be effected by deep ploughing and prodigious application of growth enhancers and humus based additives but this means the fields are temporarily out of production and of course has a marked economical penalty. It is becoming more evident that a more environmentally friendly approach is to utilise a different planting regime to both ensure a more healthy plant from the outset and encourage the enrichment of the soil through gradual breaking up of the compacted surface.
One suggested approach is to plant seeds in a machine prepared hole. This creates a micro environment under the soil crust in which the cane can begin to thrive. This should then encourage deeper root development and at the same time start to break up the hard surface of the soil as the plant grows, obviating the strangling effects of the soil compaction. The process of drilling alone breaks through the soil crust and immediately enhances the seed’s exposure to the moisture held in the sub soil. The deeper root formation within the controlled environment of the prepared growing hole means that “take up” from any root stimulant additives is maximised and because the plant is already deep it is less affected by weeds, other competitive plants and pests.
Agricultural engineers believe that adopting mechanised “hole based” planting could eventually lead to significant improvements in productivity and a generally improved soil condition in most cases. However, the process of efficiently drilling prepared plant holes (at the appropriate depth), planting the actual cane seed and providing correct doses of growth enhancer or fertiliser is complex and work intensive requiring several operations to take place.
To automate it is a complicated process which most engineers are fighting shy of, however, Samart Leethirananon, one of Thailand’s celebrated development engineers has other ideas, “It’s simply a matter of appropriately applied automation” he says. “We know what the benefits are, we know what we must do and how we must do it for optimum results, it’s just another engineering issue. We’ll solve it”.
Leethirananon comments further that to be effective a machine carrying out this process must fulfil the following criteria:-
• It must be able to drill through tough soils, reliably and to a chosen depth.
• It must have a hopper capable of holding a substantial load of seed cane
• It must feed individual lengths of seed to each of the prepared holes
• Optionally it must be able to dose the cane with appropriate growth or insecticide preparations prior to planting.
• It must provide infill to cover the cane once it has planted
• It must be economically powered
• It must be easily operated and maintained
These are the criteria laid down by Leethirananon to provide the market with a product which will enhance profit and longevity of any cane producing operation. Of course although this process helps where compaction is an issue it can be applied on prepared fields, the concept of improved plant development through optimised planting processes still applies.
Leethiranon explains further “Conceptually, precision machine planting may provide answers to compacted non-productive land, but the real answer lies in reducing long term soil damage in the first place. Soil preparation and harvesting machines with low ground pressure do the same job as those older designed machines that damage. The industry must approach this strategically so that the machine planting system becomes a short term issue whilst we work to ensure future mechanised harvesting systems are low ground pressure to minimise environmental impact”. Leethirananon concludes “A light footprint on our soil in the first place works better than any soil repair processes I can devise”.
It is clear that this concept in itself is not a new idea. Let’s face it planting is purely putting a seed in the ground. But, it has to be said that if a machine can be developed, which fulfils the above criteria economically and proves to contribute to towards enhancing the cane growing environment it would find many applications in the industry. And, with wider use in Asia we may be able to begin to reverse the trend that we are starting to see in lost cane and lost profit through soil damage. A development of this type can only be driven by Asia. Asia is where the negative environmental effect of equipment design by agriculturalists who are remote from our markets is being felt. Hopefully with this revised approach Asia will win through!