function Up()
    repeat until turtle.up()
end

function Down()
    repeat until turtle.down()
end

function Forward()
    repeat until turtle.forward()
end

function Back()
    repeat until turtle.back()
end

function TR()
    turtle.turnRight()
end

function TL()
    turtle.turnLeft()
end

function Search(item)
    for i=1,16 do
        local data = turtle.getItemDetail(i)
        if data ~= nil and data.name == item then
            return i
        end
    end
    return false
end

function Deposit()
    TL()
    TL()
    for i=1,16 do
        local data = turtle.getItemDetail(i)
        if data ~= nil and data.name == "minecraft:log" then
            turtle.select(i)
            turtle.drop()
        end
    end
    TL()
    TL()
end

function GetTrees()
    TL()
    repeat
    turtle.suck(64)
    until Search("minecraft:sapling")
    TR()
end

function GetFert()
    TR()
    repeat
    turtle.suck(64)
    until Search("Forestry:fertilizerCompound")
    TL()
end

function MainLoop()
    if not Search("minecraft:log") then
        GetTrees()
    end
    turtle.select(Search("minecraft:sapling"))
    turtle.place()
    repeat
        if not Search("Forestry:fertilizerCompound") then
            GetFert()
        end
        turtle.select(Search("Forestry:fertilizerCompound"))
        turtle.place()
    suc, data = turtle.inspect()
    until data.name == "minecraft:log"
    turtle.dig()
    Forward()
    local count = 0
    while turtle.detectUp() do
    turtle.digUp()
    Up()
    count = count + 1
    end
    for i=1, count do
        Down()
    end
    Back()
    if turtle.getItemCount(16) ~= 0 then
        Deposit()
    end
end

while true do
MainLoop()
end