English to Spanish Other Agriculture Traducción de parte de un libro

If we look back to see what has happened since WWII, the chemical companies that made the explosives, etc. for the war, converted their interests in order to use their assets. The top chemical produced during the war was nitrogen. They realized they could reuse all this in agriculture, but first they had to educate the people who would then be telling them what to do. So it began that farming took on using industrial systems...
El libro trata sobre el cultivo de cereales en un jardín propio, en casa, y la elaboración de alimentos desde una perspectiva espiritual y biodinámica en la que se tiene en cuenta la energía del universo y del suelo.
Debo corregir una tésis que es la traducción al español de parte de ese libro.