Fertiliser It’s Not All Shit

The key to a good crop is good nutrition, just like we need to eat food so does the crop the only difference being it gets its food from the soil. A crops nutritional requirements can range significantly depending on the soil and its composition, but there’s one nutrient a cotton crop always needs to make it as good as it can possibly be and its nitrogen.

Nitrogen has the chemical symbol N, is number seven on the periodic table and makes up 78% of the earth’s atmosphere, but what does this have to do with cotton? Nitrogen is also essential to building the amino acids that make up protein, making nitrogen essential to all life on earth.

So how do we get it into the fields you may ask, some of you may have noticed large tanks in my previous posts well these large tanks aren’t for holding water there for holding nitrogen liquid fertiliser (not liquid nitrogen), this fertiliser can range anywhere from 4% to 42% nitrogen. The nitrogen is then added to the channels in regulated amounts and enters the field when it is irrigated (one of the reasons why water from farms can not be added back into water ways), the nitrogen then enters the ground and is absorbed by the roots of the plants, the plant then uses it to make protein and grow.

Other ways of adding nitrogen to the field is through the aerial application of urea just before rain so it is watered down into the soil and won’t burn the plant. Another method is gassing the field, this usually occurs before planting or in the early stages of plant growth and involves adding liquid nitrogen  (yes this time I do mean the really cold stuff) directly into the soil were it turn to gas and remains for the plants to use. A natural way of adding nitrogen is through crop rotation of legumes such as the refuge crop pigeon peas (see last post “Taking Refuge”), legumes naturally create there own nitrogen through a bacteria that lives on there roots, the nitrogen then remains in the soil after the plant is gone.

I hope this answers more questions about modern farming and if you have any more questions please comment.

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Taking Refuge

Everyone takes refuge from something, just like I take refuge from the sun and heat by working nights the bugs take refuge from pesticides and GM cotton in a refuge crop such as pigeon peas. Refuge crops are crops that are not sprayed and provide a safe haven for both beneficial insects and pest insects such Helicoverpa, this forms part of Integrated Pest Management (IPM) program for cotton. So what is Helicoverpa and IMP and why do we need refuge crops?

Lets start with what Helicoverpa and IPM are, Helicoverpa is a moth that lays its eggs on the leaves of the cotton plant, the caterpillar then eats the leaves moving its way up the plant until the start to eat the cotton boll (the fruit of the plant which contains the cotton), the plant then discards the cotton boll and the yield suffers. An integrated pest management (IPM) program is a way to effectively control pests using a combination of controls such as biological, chemical and mechanical. Using a variety of controls prevents resistance building up and allows for more effective controls. So what does this have to do refuge crops?

With the introduction of GM cotton we have been able to reduce the use of pesticides by over 80% because the cotton plant has had a gene spiced into it that gives it a natural resistance to Helicoverpa. If the only control method used is the GM cotton than the Helicoverpa will build up resistance and it won’t be as effective, the same goes if only GM and pesticides are used, the resistance will build up to quickly. So if we allow populations of Helicoverpa to live in refuge crop unaffected by pesticides and GM they will mix and breed with resistant Helicoverpa and help to lower the overall level of resistance in the species, allowing our methods of control to work for a longer period of time.

I hope this helps to explain more about what we do and why GM is benefiting farmers. If you have any questions feel free to comment.

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