Curtis grew as many as 70 different types of crops in much even bigger pieces of plots. Due to this, the amount of man hours needed to ensure that everything worked out as required was high. We see from the article that, the author had to figure out why he was getting very little profits than expected. He had to plan again on the crops to grow as some were bringing high profit levels (80% of total income). He also planned on the market or the clients of his produce so as to maximise on his profits. After planning and making decision on what to do, he specialised on only 15 crops and that was the time he realized the highest profits from smaller farm sizes and less work hours.
This seems more like a rough draft than a book. Unfinished thoughts, poor organization, typos galore all combine to make an awful mess. This needs a few rounds of revision before putting it up on amazon.