When you spend time in a wild or unmanaged place you start to notice how different plants end up in distinct locations. Often a species will grow over a wide area only to suddenly stop as if some invisible barrier is holding them back. Each species is adapted to be competitive under a particular combination of factors of soil, water, aspect, microbiome, herbivore pressure, and a hundred other factors including plenty that are probably unknown or poorly understood by science. Zero input agriculture is all about finding ways to match plants to locations that they genuinely like and accepting that most species wont do well in most locations without heroic ongoing interventions (and that you are better off accepting that you can’t grow everything).
The property was mostly in low pasture when we took over, predominantly kikuyu and sour paspalum mixed with Vigna parkeri with large dense stands of Setaria in three different places. There were a few mature trees in the paddocks, and dense remnant rainforest along the creek edge dominated by water gums. Weekly rotational grazing of our small beef steer herd increase pasture diversity over a few years. When pasture die back came through and killed over 90 % of the kikuyu and sour paspalum the Bidens and fleabane took over much of the property, though the Setaria unfortunately wasn’t affected. Luckily this happened as we transitions from cattle to goats, and the Bidens is good feed for them. A wider variety of new pasture species are establishing through the Bidens, including Rhodes grass, Gatton panic and Desmodium.
Our rainfall is pretty ample on paper, averaging around 1500 mm per year, however it varies a lot year to year. We normally get more rain in the summer but it often doesnt arrive until fairly late into January. Autumn is pretty reliably damp with soil moisture decreasing into spring. Every five years or so we get a drought with rainfall failing for about six months, and about as often we get a tropical cyclone settling over us and dumping extra rain, often causing the creek flats to flood briefly. Late spring and early summer are often hot and dry. We get occasional light frosts most winters in low lying areas, but every now and then get a harder frost. Summers can climb into the low 40 C range but only if it is dry. When it is humid a maximum of 35 C is more typical.
The block is mostly hills of moderate slope with various aspects to all directions in different places. The eastern boundary is a permanent creek with a small amount of creek flats. The soil on the hills is predominantly a brownish cracking clay that has a layer of quartz about 30 cm down with heavier yellow clay beneath. There are smaller patches of more reddish soil, plus somewhat deeper and siltier soil on the creek flats. Four dams were constructed for cattle water before we took over. The smallest one with the smallest catchment can completely dry out during a drought, while the bigger ones have come close.
After some issues with goat health I got around to getting soil and pasture nutrient testing. It showed some interesting points but was mostly pretty average. The main stand outs were a calcium:magnesium ratio of 1:1 where most soils are 2:1. This can potentially stress dairy animals where this ratio is critical for udder health. Soil organic matter in our shabby weedy pastures was 7 %, probably higher than in my new vegetable gardens judging by relative soil texture. Mineral levels were otherwise satisfactory, one benefit of having a heavy clay soil. In this humid coastal zone minerals have been leached out by rain for about 25 million years since the local mountains were built by volcanic activity, unlike much of the northern hemisphere where glacial activity restored soil minerals much more recently.
This region is however one of the most geologically diverse on the planet. Every time I dig a hole I find something different, with powdery blackish soil on one side of the farm and porous red on another. Our neighbor had a bore drilled and it showed extremely varied geology with layers of grey gravel, many types of clay including pure white kaolin, among other oddities. This variability has the advantage of a high chance of a particular plant being able to grow well in at least one place on the farm. The disadvantage is it takes extra trial and error to match plants up with that location, and if I want to grow a particular species over a larger range sometimes I find they simply refuse to grow well beyond a certain point.
On paper this is about as ideal a location as you could want, with a mild climate, moderate rainfall, plenty of space and reasonable soil. The main disadvantages are variable rainfall and limited flat ground for cropping that is vulnerable to brief floods at any time of year. If it isn’t possible to feed two people on 40 acres without ongoing inputs then we may as well just go back to hunting and gathering once the global population crashes back to a few tens of millions of people. Time will tell, and the 20 odd years until I hit 60 should be long enough to answer the question to my satisfaction one way or another.
Zero Input Agriculture 