When creating a crop with a block, the "cross" model does not allow the crop to stick to the farmland

When creating a crop with a block, the "cross" model does not allow the crop to stick to the farmland.
Indeed the crop does not stick to the farmland and leaves 1 empty pixel between the farmland block and the crop itself. We can say that the crop floats above the farmland.

How to solve this problem without changing the cross to crop model ?

Thanks.