阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。
Recently it has been observed that more and more people are switching to organic vegetables and fruits. They are (nature) and safe for the human body to consume. Organic farming __(increase) and evolved in a large way due to this large demand by now. Farmers are getting better at the art of growing organic vegetables and there are many helpful tips __ they share with other members of the organic farming circle. you are a gardener and interested in growing organic vegetables, is wise to be aware of these tips and choose the best organic garden tip that helps garden to produce healthy and better vegetables.
One helpful organic garden tip that works well for all farmers is (make) your own fertilizer. This is kind of fertilizer made of dry leaves, fruit peelings and kitchen food disposables. These materials are buried underground and kept there some time. With fermentation（发酵）taking place the soil becomes richer with nutrients. This means you get a fertilizer that does not have chemicals at all. This fertilizer enhances the soil and so the vegetables and fruits are (health) and better.