OCR Text |
Show Crop Production Essentials. For tho production of our common farm crops thcro aro a fow essential things thnt must not bo overlooked, If wo expoct to find a profit in our farming. Ono of theso Is a soil on which tho solid water called tho water wa-ter tablo stands thirty Inches or moro below tho surface. Wo can grow plants In almost any soil If. tho ruiec' J nlcal arrangement of Uio soil ;tHis is right, and if tho wator oup-L oup-L pjso balanced In tho soil that foot '.y attraction will simply draw JjgljTof it to keep a Oiln film of water around tho soil particles and around tho seods or rootlots in tbo soil. This water film Is not thick enough to prevent tho operation ot the air In tho soil, tho gases ot which aro appropriated by tho plants. This wator balance is ono of tho essentials ot crop production. Another factor is heat, which must bo not only in tho air but also In tho sol). Why plnnts need heat in tho soil to help them grow we do not know, but it appears to bo necessary. Ilcnt Is surely needed in tho nlr over tho plants, as has beon demonstrated by all oxperlenco. Tho greater tho supply sup-ply of heat tho moro rapidly Is tbo water drawn through tho plants from below with its supply of Bolublo plant food. This rapidity of movement Is controlled by tho evaporation of tho molsturo from tho surfaco ot tho leaves, which evaporation is tho great pump that keeps up tho circulation of tho sap. " Another factor of plant production Is to hnvo all tho elements ot plant food present In tho required propor tions, ir nil but ono nro abundant tho lack of thnt ono will provent tho growth of tho plnnt. If ono is in smnll supply relative to tho needs of tho plant, tho dovolopmcnt of tho plant will bo meager. Nitrogen cannot bo substituted for potassium nor potassium potas-sium for phosphorus. Tho plant demands de-mands a certain proportion ot each nnd will not grow without it |