Building soil in a greenhouse!

Hi everybody!

I am currently assisting families on the steep slopes of southern Ecuador.
Many of which have greenhouses which have been dug a foot or so into the mountain side... because of this there is a lack of healthy organisms in the soil and i believe what they have essentially done is removed the top soil.

Can anybody suggest ways of building soil? I am introducing them to compost however a lot of it will be needed to cover the size of the greenhouses... which are about 80m x 20 m .
I have been considering lasagne bed technique... but many use plastic sheeting to suppress the weeds, which is another obstacle.
Mulching / ground cover? but this could take a very long time. I understand theres no 'quick fix solution' but suggestions would be great.

Another issue we have seen is some greenhouses have an abnormal amount of insects and pests... I believe it is because there is not enough airflow in the greenhouse. so it has literally become an incubator for pests? Is this true, and can anyone provide solutions. (pests included are white fly for strawberries. Caterpillars. Beattle larvae. Cabbage moth, and many more.)

Thank you for your time and help!!!

Here's a list by Bryant RedHawk on soil building.

Bryant RedHawk has an account named B RedHawk also!

In my greenhouse, I mainly use mulch to keep fertilising the soil, but I did start with a small truck-load of high-organic-matter soil brought in from nearby. In my old greenhouse I had to carry my water up from a short distance, so I had to water the greenhouse with buckets, and saved all my greywater with a container under the sink, and used that to water the greenhouse. Now I've got a hose and other plumbing, so my greywater no longer goes into the greenhouse garden, so I'm relying on mulch, and a small amount of compost that I'm making. But still, mulch left in place really breaks down, turns black and mouldy, and the soil below it starts to looks great. But people who have strong garden experience that does not include mulch may be unwilling to try it or believe it.

After another year or two when I empty my composting toilet for the first time, I will get a huge influx of organic matter.

In the greenhouse, I get aphids (is that what you are calling white fly?) kind of no matter what. You're right, insufficient air flow seems to encourage them; excess heat and excess fertility also encourage them. Eliot Coleman, who wrote two incredibly useful books about winter vegetable production using greenhouses etc, blames the build-up in fertility for aphid population booms. He points out that because of the humidity stuck in the greenhouse in winter, we tend to not water much in winter, and then the fertility can be too much. He says when he started watering once a week or so in winter to flush the soil, he saw a great reduction in aphids. I don't see such a great reduction in aphids even when I water in winter, but maybe some. I have always squished aphids. Now that I have a hose in the greenhouse, I squish aphids only on the smallest plants, and on the larger plants I use a strong jet of water from the hose with my thumb. That works pretty well.

Caterpillars including cabbage butterfly larvae don't seem to be worse inside or outside the greenhouse for me. Of course, screening the ventilation should prevent the butterflies getting in. Here we get the "large white cabbage butterfly," whose larvae are hairy and cluster in horrible big groups. Yuck!!!