Week 0: Part 2, A retrospective on decisions made on what to plant and where.
Although my planning spreadsheet has been completed and spring's crops are already in the ground (It's now week 2, more photos to be posted) I earlier promised to provide more details on the planning process.
Searching online for details about crop rotation yielded many different theories and types, varying between the common 4 year rotation systems , up to complex 8 or more year rotation plans designed for large farming systems.
Crop rotation serves 3 important purposes, firstly ensuring that plants are grown in the most suitable soil, soil condition changes as plants take out nutrients, or conversely as decay products add nutrients back in. Secondly rotation serves to separate plants from disease causing organisms which may build up in the soil after several years of growing the same crop. Lastly, by dividing available space into smaller areas of different plant types allows for more diversity, reducing the risk of catastrophic crop failure affecting one species.
Space restriction made me wary of going for anything more than a 4 bed system, also I doubted I would have the attention span to continue for so many years, and lastly it seemed like there was a simpler method i could use. Most rotation plans included the following phases,
Fallow: where the land is left by itself for a year, to be colonised by whatever happens to grow there by itself, the idea is that whatever weeds pop up will compete for nutrients, they will bring nutrients up from deeper in the soil, if there is a nitrogen deficiency clover or other nitrogen fixing plants may thrive, overall there should be a balancing effect on soil nutrients and PH, also it helps to re-establishing soil biota which may be stressed by monoculture crops, and lastly it can help break pest and disease cycles by hosting other benificial organisms like insects which may prey on pests of your other crops.Finally the fallow land is ploughed under allowing all that grey there to decay into the soil providing rich fertiliser for the next crop.
Nitrogen hungry crops :Cereals like corn and wheat, leafy plants and brassicas, have high nitrogen requirements, they grow best in the richest soil and as the nitrogen is concentrated in the leaves or in cereals where the main concentration is in the grain, it means that after harvest whatever waste ploughed back into the soil is generally low in nitrogen
Neutral Restricted crops: these crops need nitrogen to grow, but excessivly high nitrogen levels result in too much leaf growth and not enough harvestable vegetable material, includes root vegetables, fruit crops like tomatos, curcurbits, etc.
Acid lovers: these plants prefer the slightly acidic soil that is left over from a year of growing nitrogen hungry crops, examples usually include tomatos, Radishs and other root vegetables, brassicas, etc.( more research shows most plants to be rather tolerant of a fairly low ph level, ranging from moderately acidic to neutral)
Legumes: Grown for their nitrogen fixation abilities, all kinds of peas and beans can host the correct type of bacteria in their roots, also includes clover, alfalfa and other nitrogen fixation plants include certain larger shrubs and trees such as acacia . In fact i may have some of these growing as weeds in my own backyard.
Compost: not exactly a planting type, but most rotations provide for some time spent between crops composting waste from previous seasons, a common variation being fields left bare in winter but covered in all the waste stored from everything grown that year. Less common would be a rotation scheme which includes one plot left to compost for an entire year, with most waste produced by all other plots added to it over the year. This field is usually rotated to be as far as possible from the legume field in order to provide 2 high nitrogen periods over the rotation plan.
Other rotation plans include dividing plants by type, such as onion, brassica, fruiting types like tomato and capsicum, and then planting in companion planting groups, avoiding combinations which detriment plant growth etc. examples include not planting onion and beans together or brassicas and capsicum. Also planting speces which deter or distract pests of crop species.
I eventually settled on a 3 bed rotation as it seems nitrogen levels are the main limiting factor in plant growth, divided into 3 allows a year spent building nitrogen levels, 1 year for plants which heavily draw nitrogen away then 1 year growing plants which are satisfied using the poorest soil. Interspersed throughout will be various strategies intended to maintain nitrogen levels, nitrogen fixing cover crops, composting, application of manure etc. The legume field will host corn and cucurbits early in the season, which will be fed by fertilizer at the start of the season, then mulch during the season, changing to at least an entire season of nothing but legumes, the nitrogen hungry field will need to receive applications of fertilizer between seasons, and the low nitrogen field should benefit from a cover crop of clover, especially due to the slow growth time of the tomato and capsicum plants. All crops will get slight benefit from some mulch added around the base of the larger plants, also nitrogen from weeds pulled and dumped back into the field.
Now that the rotation is determined, I needed to Select where to place the available plants, and in which order and season.
Another update should be necessary.