在香港做生機互動比在外國難，土地不多，連飼養一隻牛也很困難。在沒有牛或動物，沒有動物糞便的情況下，我們只可以做到以雜草做的堆肥。由每次除草，收集，到做成一個堆，動輒用上一至兩個月時間，非常艱辛。但當看到種出來的植物有其本質，菜是菜，瓜是瓜的時候，再辛苦都覺得值得。
為什麼要做堆肥，而不直接用買回來的肥料（不論是「有機」還是「化肥」）？
在史代納博士農業八課以外的演講，農夫太太讀到這段文字：
You can see that it is also a question of giving proper nourishment to the plants themselves. And that means, we must realize that plants are living things; they are not minerals, they are something alive. A plant comes to us out of the seed we put in the ground. The plant cannot flourish unless the soil itself is to some degree alive. And how do we make the soil alive? By manuring it properly. Yes, proper manuring is what will give us really good plant protein. We must remember that for long, long ages men have known that the right manure is what comes out of the horses' stalls, out of the cow barn and so on; the right manure is what comes off the farm itself. And you can see, gentlemen, when one uses mineral fertilizer, it is as if one just put minerals into the ground; then only the root becomes strong. Then we get from the plants the substance that helps to build up our bones. But we don't get a proper protein from the plants. And the plants, our field grains have suffered from the lack of protein for a long time. And the lack will become greater and greater unless people return to proper manuring. There have already been agricultural conferences in which the farmers have said: Yes, the fruit gets worse and worse! And it is true. But naturally the farmers haven't known the reason. Every older person knows that when he was a young fellow, everything that came out of the fields was really better. It's no use thinking that one can make fertilizer simply by combining substances that are present in cow manure. One must see clearly that cow manure does not come out of a chemist's laboratory but out of a laboratory that is far more scientific — it comes from the far, far more scientific laboratory inside the cow. And for this reason cow manure is the stuff that not only makes the roots of plants strong, but that works up powerfully into the fruits and produces good, proper protein in the plants which makes man vigorous. Lecture 7 1924