Conservation Farming Principles

I found this line on the Sweet As! blogsite, by Qld Nuffield Scholar and sugarcane grower Bryan Granshaw

“it has taken us 10 years to get to the point where we can implement all four priciples of conservation farming, which are, Controlled Traffic (RTK GPS and all axle widths match row spacings), Cover Crops (Legumes), Minimum Tillage, Crop Residue retention(ground cover). It is a system that delivers costs savings, builds soil health, over time improves production, and importantly has less potential for off site environmental impacts.”

I can relate to the desire to farm by principles – RTK CTF, CC, NT or ZT, and SRR (surface residue retention).  How’s that for acronyms?  “SRR” I have never seen before, but I reckon there are enough results in a web search to make it up and warrant its use.  The principles fit together, and have been shown to be practicable in various parts of the world.  They can be separate from and be plans to be biological or organic, low or high input, livestock or without.

And I can relate to the “10 years” issue of even getting started properly when moving toward CTF – in annual cropping it took me a few months to enjoy the benefits of spraying on crop tramlines, then another year to interrow sow, and then the benefits of tramlines compound in following years.  RTK, with memory,  is the only way to go – 10cm accuracy systems allows too much drift with satellite movement.  “Minimising compaction”  has its detractors, but I have seen enough in my climate on my soils to know that machinery wheel compaction exists, reduces yield, uses more fuel etc, and have been able to make a non-header system work.  If I can do that, then no wonder a full system works well.

CC (cover crops) can be mono or poly-cultures, summer or winter, ground or aerial sown, and this blog concentrates on the use of summer mixtures of species.

NT (tyne with minimal soil throw or disc with some) and ZT (Zero Till with disc), which goes together with SRR (mulch) as opposed to partial or full stubble/residue burial.  I take the SRR side of the debate, and a large debate it is (“tillage burns more humus than it creates”  – discuss….) I even lean to standing stubble (it will fall or be harvested to fallen mulch soon enough), but will acknowledge suggestions (trial data, uncited) that humus levels build differently in different soils and climates.

The hard work comes in the planning and making decisions, basing them on the principles.  How wide do I make/purchase machinery?  Wheel spacing?  Tyne/disc spacing?  Can I spread my straw and chaff wide enough? How much residue can any and all operations handle?  Etc.

Did I mention I wasn’t going to argue about “Why cover crop?”

AZUKI BEANS in a Cover Crop Cocktail Mix

AZUKI BEANS

Although I haven’t trialled them yet, I must have come across a report (presently unciteable) which mentioned azuki beans, also known as adzuki beans, as a cover crop option in tropical areas.

According to the Wikipedia azuki bean entry,  they seem to be common worldwide, as a foodstuff.  Maybe that is why I have them in mind, but I don’t consider them a serious contender as a cover crop spp.  Speaking to a grain trader lately, I learned that seed is hardly available here and dear enough ($1500/t).  He also warned me they are a thirsty crop and hard to grow even under irrigation.  I should have asked him if that was for biomass as well as seed.

I wonder if they are too soft for dry hot summers?  The grain size (5mm) reminds me of vetch which is a spp I am not keen to grow, cool or warm season, since any winter growth in our lentil phase of rotation can downgrade samples.  Vetch can neither be sprayed out of lentils nor cleaned out of the seed, or at least not easily.  If azukis only germinated in spring or summer then we could get away with it, and since they won’t be going to seed, it is only the hardseeds which present the hazard.  And that is the issue with any species considered in a cover crop mix, to not let it interfere with the cash crops.

Admittedly azukis are one of those longshot ideas, like the purple king beans, and dwarf beans I tried.  And any legume amongst the mix will be displacing cowpeas and lablab as the staple legumes, so they need to be pretty good, even if only to add to genus diversity.

So, should I small-plot trial them anyway?

AMARANTH in a Cover Crop Cocktail Mix

Amaranth

A is for Amaranth.  As the Sage of Omaha said, (to paraphrase), “With all those stock names to study, start with A.”

Amaranthus has over 70 species in the genus, according to Wikipedia http://en.wikipedia.org/wiki/Amaranth

I have seen amaranth listed as a good sp to include in a cover crop mix, but have found little online evidence of it being used.

It is supposedly a low water use, warm season plant, which comes up quickly, and grows slowly in the heat, and is tolerant of drought and heat.  I’ve also heard, (thanks Gabe B.!) and see the point, that if we sow such a small seed in a mix at depth, the larger seeds break the surface and make it easier for small seeds to come up.

Varieties

In discussion with seed suppliers, of which I can find a few who will sell small packets, and will discuss larger amounts, the grain cvs are preferable, eg Hydrochondriacus.  Tricolor, Bicolor, cruentus, caudatus, gangeticus are other possibilities.

Trial Result.

I have trialled them this year, to find them germinate and grow in the watered garden, sown early Jan, but to produce little in 4 months, and then go to seed.  In the paddock they were lucky to germinate, then died for lack of moisture (making chia look good).  Or could it have been from SU residues, from the previous year or ealier?  A successful trial, in that it shows what will happen in those circumstances.  I wonder what would happen with an early December planting, with more moisture.

Amaranth as a weed.

I am concerned that they could become a weed.    Amaranth is notorious for being hardseeded, so if anything is sown this year, could it germinate next spring and become an in-crop weed?  Red root amaranth around here is a weed which is already seeding in the summer.  Palmer amaranth is not only a bad weed in NSW, there are apparently areas resistant to glyphosate.  We don’t need that here.

What is the global experience with amaranth as a part of a cover crop mix?  Species, varieties?

Wind Erosion and the Role of Cover Cropping

Good Friday 2012.

We may not have had darkness for 3 hours today, but the dust storms from local wind erosion went some way to blacking out the sun.

These pics speak for themselves, and go some way to answering the question “Why?”  Why no till, why cover crops, why continuous ground cover, why limit stock grazing?  Much of the land here will never erode like this, even with multiple cultivation and no stubble cover.  But much will, especially if sandy, and with stubble just burnt.  Often the land can get away with being bare for a month or two until the next crop provides cover.  But not always.  It only takes a few hours of high winds to bury fences (I’ve seen it often, and I’ve been responsible for some.)  And there is a high chance of getting that sort of weather in Autumn, when land is prepared ready for sowing, flat, bare and dry.

Pardon me for having some attitude about it.

My Secret Identity

For now, I’m going to stay anonymous to the world.  Let’s see how long that lasts…

Hello world! A blog about Arid Zone Summer Cover Cropping

Welcome to my first ever blog post.

The intention is to share ideas and seek advice re summer cover cropping in my area.

You see, in some circles the idea of growing a non-cash crop, to be brown or green manured    for the sake of building up soil health is neither new nor uncommon.  Growing vetch here for incorporating is sometimes done.  In gardening and organic circles it seems it is commonplace.  And in the USA there a whole cover crop seed industry spanning over a decade.

But not here.  Right here we have an average 14.5″ yearly rainfall, growing season around 10″ (250mm) from April to November.  Cool season harvest begins around mid November, and sowing around late April, depending on attitudes to risk.  That leaves a window of December to March to have something growing, harvesting sunlight, using up shallow moisture which is doomed to evaporate anyway, and feeding soil bugs with root exudates.  Normally summer weeds will depress the next cash crop yields, and keeping them dead, with singular or multiple spraying passes can easily be a good investment.  Summer weeds suck up moisture, nutrients and in many cases end up in the way.  They could be, for all I know, be depressing cash crop yields in other ways not so obvious (allelopathy, pest and disease contributions, etc).

I intend to shout out to those who have given their time to conversations, to let them in on my progress, to discuss species and cultivar choices and supplies, and hopefully contribute to the building of what could become a growing industry in Australia.

This is NOT to debate or defend the idea.  I don’t know if it will work here, or if it will be profitable overall.  If not, it might explain why for the last 6 months I haven’t found anyone in the whole of Australia doing what I have in mind.  (Or maybe they know it is an unusual practice and are keeping quiet.)  I have met and spoken with some who are making it work, albeit in different parts of the world with different soils and climates.  I will welcome some debate:  feel free to ask “Why (that detail)?”  But there are plenty of other resources to learn about ‘Why cover crop at all?’  I won’t tell you why, and I won’t spend time trying to defend the idea, even if it seems crazy and paradoxical.  Go, google, read, learn, then come back.  I believe the idea has merit, and I intend to find out in the paddock.  It is the joy of being a self employed farmer, albeit a two-edged sword;  we live what we believe.

So, since a blog can garner global views, this is my next step.  Especially since it is many months now till I sow the next ‘summer crop’ trial.

I will probably touch on some other ideas as well, related to ‘how to grow a better wheat crop’, especially as it relates to trials.