Lack of nitrogen is
generally the early warning sign. Since I've been trying to use only
on-farm compost and manure this spring, I ended up with a few
low-nitrogen spots that required topdressing.
I wish I'd taken a
picture of the peppers above before their dosing so you could see the
difference a thin layer of chicken-manure bedding between the rows
created. The leaves were slightly yellow at that time, but mostly the
plants just weren't growing the way they ought.
I wasn't really surprised by
the problem because I'd treated the bed to the last of our garden
compost pile, which is much lower in nitrogen than composted manure.
Then I'd laid down a weed-control layer of newspaper (high carbon) and
weighed that down with a thin layer of homegrown rye tops (also high
carbon).
Luckily, garden plants
are resilient beings. A week after getting their extra nitrogen dose,
the plants greened up and started growing. A week after that, we had
our first ripe lunchbox pepper.
Definitely worth feeding
the soil a little more so the soil will then feed us!
Do you know if using newspaper and black plastic keep out atmospheric nitrogen?
Do you have any controls to study this?