Walking through the fields today really made me miss the AP Enviro chapter on Agriculture and Food Production (I'm thinking of going back and re-reading the PowerPoint), and though you guys probably haven't done that chapter yet, I just wanted to share with you all a bit of what I learned!
Today, Nanaji ("grandpa" in Hindi) took me out to see what happens to the trees after they have been harvested. The first step is to remove any deadwood, and apply a fungicide (paste, paint, or spray) to the spot where the dead branch used to be.
The next step is to apply fertilizer. Nanaji described to me the three times when doses of fertilizer are administered to the kinnow plant -- 1) just after the fruit has been plucked, 2) when the fruit is a bit larger than the size of a pea, and 3) when the fruit is lemon-sized. Sometimes, fertilizer is also applied soon before plucking the fruit.
There are two primary methods of applying fertilizer -- foliar application and soil application. The first is what I observed today. In foliar application, the fertilizer is sprayed directly onto the leaves of the entire plant (the word "foliar" is derived from the Latin word folium, meaning "leaf" and is related to the word "foliage").
The second technique, soil application, consists of applying fertilizer in a powder form to the soil underneath the plant, as far out as the roots of the plant extend. The Nitrogen, Phosphorus, and Potassium (N, P, K) leach into the soil and enter the plant through its roots.
Nanaji also showed me examples of drip irrigation, the primary method of irrigation used on our farm. Each plant is encircled by pipes, which have small holes in them so that when water runs through these pipes, some of it is given to the plant. More and more lrings of pipes are added as the plant grows bigger. (Imagine looking down from the sky and seeing a target surrounding the trunk of the tree.) Fertilizer can also be mixed into this water supply so that the plant receives both water and "food" as it is irrigated.
I think that's all I remember from today's tour, but I'll be sure to post more as I come across it. As always, feel free to email me at email@example.com any time at all!