PLANT GROWTH. 



By Forest Henry, Dover, Minn. 



We have met today to study plant growth and animal life. It 

 is the business of the farmer to make the conditions such that 

 the animal or plant that he has under his care can do its best. 

 The great majority of farmers think that a plant grows entirely 

 from the soil. This is not true. The greater part of the food 

 a plant takes it gets from the air. The gasses of the air com- 

 bined with bright sunshine form the starch of the plant in the 

 plant's leaf. The leaf is the laboratory where this work is car- 

 ried on. In other words, the leaf is the stomach and lungs of 

 the plant. How necessary then, it is that a plant has a good 

 leaf growth. Every farmer knows that when the potato beetle 

 eats away the leaf of the potato plant his potatoes will be small 

 and few in numbers. It is because the potatoes contain starch/ 

 which can not be stored up when the leaf growth has been de- 

 stroyed. While it is true that the bulk of the food that a plant 

 takes it gets from the air, it is also true that certain elements 

 of food it takes from the soil, and it is very necessary that the 

 soil has these elements of food in a form where the plant can 

 make use of them as needed. Nearly all soils have an abund- 

 ance of mineral plant food stored up in them ; but very little of 

 it is in a form that the plant can use. We say it is locked up. 

 All mineral plant food must be in a condition so it can be taken 

 up in solution in water before the plant can make use of it. 

 We buy commercial fertilizers so as to get this plant food in 

 a liberated form or in a form where the plants can use it right 

 away. The farmer should rather liberate these mineral plant 

 foods in the soil so far as possible and save his money. One 

 of the best ways to do this is to introduce vegetable matter into 

 the soil. When this vegetable matter begins to decay it forms 

 huniic acid which eats away little particles of these mineral 

 plant foods and thus puts them in a condition so water can dis- 

 solve them. Another way to liberate plant food is by tillage. 



