Buying new equipment: sower | Agriculture Farming Simulator 2013 Guide

Out of all the machines that you have, the least efficient is the AMAZONE D1 sower, by which I mean that it's the slowest at its job when compared to the cultivator or harvester (both of which have a wider working area), not to mention the sprayer. Therefore it should be the next one in line to update. First however, you can take the old sower to the shop to sell it for 3 780 $ (instead of 3 159 $ from the menu level).

Time to buy a new, better sower.

Your current sower has a sowing width of 2,1 m. I'd recommend buying the AMAZONE D9 3000 Super for 11 500 $ - considering that you sold your old one, the real cost of the investment will be around 8 000 $. Unfortunately the new sower cannot be used with your old tractor. There are two options here: you can alternate between using the newer tractor with the sower and cultivator (though you won't be able to do those two activities simultaneously on a big field, i.e. drive the sower right behind the cultivator).

Better implements require more powerful tractors to pull them.

You can also sell the awful tractor (12 600 $ if you take it to the shop personally) and buy a new, better one. Basically your choices here limit to three models: SAME Argon3 75 for 57 000 $, Buhrer 6135 A for 65 000 $ and URSUS 15014 for 74 000 $. As you should already have the first two - considering you followed this guide - the third one should be your tractor of choice.

If you already have or just bought the SAME Argon3 75, buy an additional weight and mount in the front. Attach the new sower at the back. Note that when you have two implements attached at the front and in the back, you can switch between them (which is visible in the lower right corner by the tractor icon) and control them separately.