Hello!
If you stuck with small field yield, then this mod is for you!
Mod name I guess is self descriptive, so all this mod is doing - is incease field yield plus few more nice features like reduce seeds and fertilizer usage.

Usage:
Install as usual mod.

Predefined settings:
wheat - 10x increase
barley - 8x increase
oat - 6x increase
cotton - 2x increase
canola - 6x increase
sunflower - 4x increase
soybean - 10x increase
maize - 6x increase
potato - 2x increase
sugarbeet - 2x increase
oilseedradish - 2x increas
poplar - 2x increase
sugarcane - 2x increase
grass - 6x increase
drygrass - 6x increase

Seeds usage for several crops sliglty reduced.
All fertilizer usage is reduced to a bit as well.

Configuration:
Style, you need to do next:
1. Install mod and launch the game. That will generate settings file, which you may find here:
"C: \ Users \ {username} \ Documents \ My Games \ FarmingSimulator2019 \ modsSettings \ EnlargeFieldYield \ enlargeFieldYieldSettings.xml"

2. Open enlargeFieldYieldSettings.xml and edit next attributes:
For crops:
- seedUsagePerSqm - control amount of seed usage. Lower value => less seeds will be used.
- literPerSqm - control yield amount. Lower value => less yield you want to get.

For Fertilizers:
- litersPerSecond - control amount of fertilizer usage. Lower value => less fertilizer will be used ..

Attributes like defaultSeedUsagePerSqm, defaultLiterPerSqm, defaultLitersPerSecond I give for orientation what is in vanilla game.

Error free.
Works in multiplayer.