Fertilizer is food for crops. There are now more than 22 known nutrients needed for crop growth. Among them, carbon, hydrogen, and oxygen can be obtained from air and water, and generally do not need to be provided in the form of fertilizers. Nitrogen, phosphorus, and potassium have higher contents in crops and are absorbed more, accounting for several percent to several thousandths of the weight of dry matter. They are called "macroelements". Nitrogen, phosphorus, and potassium are generally less abundant in soil and need to be supplemented in the form of fertilizers, so they are specifically called the "three elements of fertilizers." Calcium, magnesium and sulfur are generally called "middle elements". Elements such as copper, zinc, iron, manganese, boron, and molybdenum are required by crops in small amounts and are called "trace elements."
Reader comments
The book clearly explains the classification and functions of fertilizers, and also mentions the effects of various elements on crops. I particularly like this simple and clear style, without being wordy. However, I kind of hate those people who sell fake fertilizers. They are simply cheating farmers out of their hard-earned money! I hope this book will help more people learn about fertilization and stop being deceived.
The book clearly explains the classification and functions of fertilizers, and also mentions the effects of various elements on crops. I particularly like this simple and clear style, without being wordy. However, I kind of hate those people who sell fake fertilizers. They are simply cheating farmers out of their hard-earned money! I hope this book will help more people learn about fertilization and stop being deceived.
Very good. Very good. Can still listen.