Q. What are the Combines?
A. There are TWO types of Combines and they come in several sizes.There are requirements to be able to purchase the bigger combines.
ALL of the Combines use Fuel.
The 5x5 combines 5x5 and larger sizes, all cost Farm Cash.
The 1x1 combines do not require purchasing and are already in your yellow toolbox, they are at the very bottom of the column of combines.
The 1x1 combines work on one field per click.

Combine Harvest-Plow tools will harvest crops and plow fields with each click of the tool. It uses fuel for Harvesting not for the Plowing.
Combine Harvest-Plant tools will harvest crops, plow fields and plant new seeds with each click of the tool. It uses fuel for the Harvesting and Seeding not for the Plowing.
When you own at least one Combine Harvest-Plant tool, if you often plant more than one different crop on a farm or perhaps may have a farm with many different crops on it for Quest purposes and replant the same crops on it often, you may also like the upgrade to these tools. The upgrade enables a replant method so that you do not have to keep selecting different crops when you are planting the exact same ones. If you would like more information on this please click on this link to read up on what and how to use the Crop Replanter Implement: https://www.slashkey.com/forum/showt...14#post6579414
These combines are NOT the combines that can make working overlapped crops faster. Overlapping fields is still not officially supported by the developers, BUT you must own all the sizes up to and including the 16x16 before you can buy your first EX Combine-Plow or EX Combine Harvest-Plant to be able to work overlapped fields faster.
For full details on ALL the crop tools tools that can work overlapped crops faster click on this link:
Are there tools for working overlapped fields?
For the larger size tools to be able to get the maximum amount of fields per click your fields must be plowed close together and in line with each other. If the fields are offset the tool either won't be able to get them all or will try to grab an odd pattern.
To buy the 5x5 Combine Harvest-Plow and larger sizes, you must own the relevant size Harvester and Plower before you can buy the same size Combine Harvest-Plow.
- Combine Harvest-Plow (5x5) will harvest and plow up to 25 fields in a squared 5x5 area.
- Combine Harvest-Plow (6x6) will harvest and plow up to 36 fields in a squared 6x6 area.
- Combine Harvest-Plow (8x8) will harvest and plow up to 64 fields in a squared 8x8 area.
- Combine Harvest-Plow (10x10) will harvest and plow up to 100 fields in a squared 10x10 area.
- Combine Harvest-Plow (12x12) will harvest and plow up to 144 fields in a squared 12x12 area.
- Combine Harvest-Plow (14x14) will harvest and plow up to 196 fields in a squared 14x14 area.
- Combine Harvest-Plow (16x16) will harvest and plow up to 256 fields in a squared 16x16 area.
When you own the Combine Harvest-Plow 16x16 you meet the requirement to buy your first EX Combine Harvest-Plow.
If you are not overlapping crops you can continue buying the bigger size tools:
- Combine Harvest-Plow (18x18) will harvest and plow up to 324 fields in a squared 18x18 area.
- Combine Harvest-Plow (20x20) will harvest and plow up to 400 fields in a squared 20x20 area.
The 20x20 combines and larger sizes also enables the use of Extent Mode which shows a Blue box to work all single layer crops within that box. This does not allow working of overlapped crops with this tool.
- Combine Harvest-Plow (22x22) will harvest and plow up to 484 fields in a squared 22x22 area.
- Combine Harvest-Plow (24x24) will harvest and plow up to 576 fields in a squared 24x24 area.
- Combine Harvest-Plow (28x28) will harvest and plow up to 784 fields in a squared 28x28 area.
- Combine Harvest-Plow (32x32) will harvest and plow up to 1024 fields in a squared 32x32 area.
To buy the 5x5 Combine Harvest-Plant and larger sizes, you must own the same size Combine Harvest-Plow AND the same size Seeder before you can buy the Combine Harvest-Plant.
- Combine Harvest-Plant (5x5) will harvest, plow and plant up to 25 fields in a squared 5x5 area.
- Combine Harvest-Plant (6x6) will harvest, plow and plant up to 36 fields in a squared 6x6 area.
- Combine Harvest-Plant (8x8) will harvest, plow and plant up to 64 fields in a squared 8x8 area.
- Combine Harvest-Plant (10x10) will harvest, plow and plant up to 100 fields in a squared 10x10area.
- Combine Harvest-Plant (12x12) will harvest, plow and plant up to 144 fields in a squared 12x12 area.
- Combine Harvest-Plant (14x14) will harvest, plow and plant up to 196 fields in a squared 14x14 area.
- Combine Harvest-Plant (16x16) will harvest, plow and plant up to 256 fields in a squared 16x16 area.
When you own the Combine Harvest-Plow 16x16 you meet the requirement to buy your first EX Combine Harvest-Plant.
If you are not overlapping crops you can continue buying the bigger size tools:
- Combine Harvest-Plant (18x18) will harvest, plow and plant up to 324 fields in a squared 18x18 area.
- Combine Harvest-Plant (20x20) will harvest, plow and plant up to 400 fields in a squared 20x20 area.
The 20x20 combines and larger sizes also enables the use of Extent Mode which shows a Blue box to work all single layer crops within that box. This does not allow working of overlapped crops with this tool.
- Combine Harvest-Plant (22x22) will harvest, plow and plant up to 484 fields in a squared 22x22 area.
- Combine Harvest-Plant (24x24) will harvest, plow and plant up to 576 fields in a squared 24x24 area.
- Combine Harvest-Plant (28x28) will harvest, plow and plant up to 784 fields in a squared 28x28 area.
- Combine Harvest-Plant (32x32) will harvest, plow and plant up to 1024 fields in a squared 32x32 area.
When you buy a bigger size tool you will see a popup telling you what you are about to buy, please make sure that you read it and especially note the name and size of the tool before you purchase.
If you do not have Show Tools checked in your Show Preferences that will also be shown in the popup.
If you are buying a tool bigger than the 16x16 there is another popup that will remind you that the tool is not an EX tool for working overlapped crops.
Example:

How to use EXTENT Mode and HIGHLIGHT Mode on the 20x20 tools and larger.
When using one of the 20x20 crop tools or larger, instead of the Eye, above your yellow toolbox, you will see the picture of the tool you have clicked on. This example is showing the 20x20 Combine.

When you click on the picture of your tool located above your yellow toolbox you will see a vertical toolbar with 3 options, that you can click on.
The White X at the bottom of the options just closes the menu.

The TOP icon, HIGHLIGHT MODE, changes to the tool to using the single layer method of highlighting each individual item which you likely already know about.

When you use this method you will briefly see "Highlight mode selected" in white lettering near the top of the game screen.

The MIDDLE icon, EXTENT MODE, changes to the tool to using the New Method of using a BLUE BOX to indicate a selected area of the farm. Anything within that BLUE box will be worked on.

Extent method selects specific areas of a farm to work on with less manual mistakes then the highlight mode as you don't have to be as accurate with aligning the tool as it works on all crops within the BLUE box. When using this method you will briefly see "Extent mode selected" in white lettering near the top of the game screen.

IF you tried to use a single layer crop tool on overlapped crops you will not be able to work those crops as you are not using an EX tool which uses a Yellow box. If you try to use Extent Mode on single layer crop tools on farms with overlapped crops you will see a brief notification like this:

You would need to either use Highlight Mode on a Single layer crop tool OR switch to an EX crop tool that you or the farm owner owns to be able to work overlapped crops faster in Extent Mode.