Regrowing Saplings: Super lag efficient

summon FallingSand ~ ~1.5 ~ {Motion:[0.0d,-1.0d,0.0d],Time:1,DropItem:0,Block:redstone_block,Passengers:[{id:FallingSand,Time:1,DropItem:0,Block:activator_rail},{id:MinecartCommandBlock,Command:"summon ArmorStand ~2 ~-2 ~ {CustomName:GM4_PlantSaplings,Tags:[\"2.0\",GM4,],NoGravity:1b}"},{id:MinecartCommandBlock,Command:setblock ~2 ~-2 ~ minecraft:repeating_command_block 5 replace {auto:1b,TrackOutput:0b,Command:/scoreboard players tag @e[type=Item,tag=!GM4_PlantSapling] add GM4_IsPlantableSapling {Item:{id:minecraft:sapling},Age:5999s,OnGround:1b}}},{id:MinecartCommandBlock,Command:setblock ~3 ~-2 ~ minecraft:chain_command_block 5 replace {auto:1b,TrackOutput:0b,Command:/execute @e[tag=GM4_IsPlantableSapling] ~ ~ ~ detect ~ ~-1 ~ dirt -1 execute @e[dx=0,c=0,tag=GM4_IsPlantableSapling] ~ ~ ~ detect ~ ~ ~ air 0 scoreboard players tag @e[c=0,dx=0,tag=GM4_IsPlantableSapling] add GM4_IsPlantableSaplingOnGround}},{id:MinecartCommandBlock,Command:setblock ~4 ~-2 ~ minecraft:chain_command_block 5 replace {auto:1b,TrackOutput:0b,Command:/execute @e[tag=GM4_IsPlantableSapling] ~ ~ ~ detect ~ ~-1 ~ grass -1 execute @e[dx=0,c=0,tag=GM4_IsPlantableSapling] ~ ~ ~ detect ~ ~ ~ air 0 scoreboard players tag @e[c=0,dx=0,tag=GM4_IsPlantableSapling] add GM4_IsPlantableSaplingOnGround}},{id:MinecartCommandBlock,Command:setblock ~5 ~-2 ~ minecraft:chain_command_block 5 replace {auto:1b,TrackOutput:0b,Command:entitydata @e[type=Item,tag=GM4_IsPlantableSaplingOnGround] {Age:5998s,PickupDelay:10s,Tags:[GM4_PlantSapling]}}},{id:MinecartCommandBlock,Command:setblock ~6 ~-2 ~ minecraft:chain_command_block 13 replace {auto:1b,TrackOutput:0b,Command:/blockdata ~1 ~ ~ {auto:1b}}},{id:MinecartCommandBlock,Command:setblock ~7 ~-2 ~ minecraft:command_block 5 replace {TrackOutput:0b,Command:/blockdata ~ ~ ~ {auto:0b}}},{id:MinecartCommandBlock,Command:setblock ~8 ~-2 ~ minecraft:chain_command_block 5 replace {auto:1b,TrackOutput:0b,Command:/scoreboard players tag @e[type=Item,tag=GM4_PlantSapling] add GM4_PlantSapling0 {Item:{Damage:0s}}}},{id:MinecartCommandBlock,Command:setblock ~9 ~-2 ~ minecraft:chain_command_block 13 replace {auto:1b,TrackOutput:0b,Command:/execute @e[tag=GM4_PlantSapling0] ~ ~ ~ setblock ~ ~ ~ minecraft:sapling 0 keep}},{id:MinecartCommandBlock,Command:setblock ~10 ~-2 ~ minecraft:chain_command_block 5 replace {auto:1b,TrackOutput:0b,Command:/scoreboard players tag @e[type=Item,tag=GM4_PlantSapling] add GM4_PlantSapling1 {Item:{Damage:1s}}}},{id:MinecartCommandBlock,Command:setblock ~11 ~-2 ~ minecraft:chain_command_block 13 replace {auto:1b,TrackOutput:0b,Command:/execute @e[tag=GM4_PlantSapling1] ~ ~ ~ setblock ~ ~ ~ minecraft:sapling 1 keep}},{id:MinecartCommandBlock,Command:setblock ~12 ~-2 ~ minecraft:chain_command_block 5 replace {auto:1b,TrackOutput:0b,Command:/scoreboard players tag @e[type=Item,tag=GM4_PlantSapling] add GM4_PlantSapling2 {Item:{Damage:2s}}}},{id:MinecartCommandBlock,Command:setblock ~13 ~-2 ~ minecraft:chain_command_block 13 replace {auto:1b,TrackOutput:0b,Command:/execute @e[tag=GM4_PlantSapling2] ~ ~ ~ setblock ~ ~ ~ minecraft:sapling 2 keep}},{id:MinecartCommandBlock,Command:setblock ~14 ~-2 ~ minecraft:chain_command_block 5 replace {auto:1b,TrackOutput:0b,Command:/scoreboard players tag @e[type=Item,tag=GM4_PlantSapling] add GM4_PlantSapling3 {Item:{Damage:3s}}}},{id:MinecartCommandBlock,Command:setblock ~15 ~-2 ~ minecraft:chain_command_block 13 replace {auto:1b,TrackOutput:0b,Command:/execute @e[tag=GM4_PlantSapling3] ~ ~ ~ setblock ~ ~ ~ minecraft:sapling 3 keep}},{id:MinecartCommandBlock,Command:setblock ~16 ~-2 ~ minecraft:chain_command_block 5 replace {auto:1b,TrackOutput:0b,Command:/scoreboard players tag @e[type=Item,tag=GM4_PlantSapling] add GM4_PlantSapling4 {Item:{Damage:4s}}}},{id:MinecartCommandBlock,Command:setblock ~17 ~-2 ~ minecraft:chain_command_block 3 replace {auto:1b,TrackOutput:0b,Command:/execute @e[tag=GM4_PlantSapling4] ~ ~ ~ setblock ~ ~ ~ minecraft:sapling 4 keep}},{id:MinecartCommandBlock,Command:setblock ~17 ~-2 ~1 minecraft:chain_command_block 4 replace {auto:1b,TrackOutput:0b,Command:/scoreboard players tag @e[type=Item,tag=GM4_PlantSapling] add GM4_PlantSapling5 {Item:{Damage:5s}}}},{id:MinecartCommandBlock,Command:setblock ~16 ~-2 ~1 minecraft:chain_command_block 12 replace {auto:1b,TrackOutput:0b,Command:/execute @e[tag=GM4_PlantSapling5] ~ ~ ~ setblock ~ ~ ~ minecraft:sapling 5 keep}},{id:MinecartCommandBlock,Command:setblock ~1 ~-2 ~ wall_sign 4},{id:MinecartCommandBlock,Command:"blockdata ~1 ~-2 ~ {Text1:\"{\\\"text\\\":\\\"\\\",\\\"clickEvent\\\":{\\\"action\\\":\\\"run_command\\\",\\\"value\\\":\\\"tellraw @p [\\\\\\\"\\\\\\\",{\\\\\\\"text\\\\\\\":\\\\\\\"[GM4] Regrowing Forest V2.0 Click for Updates, Commands & Info\\\\\\\",\\\\\\\"color\\\\\\\":\\\\\\\"aqua\\\\\\\",\\\\\\\"clickEvent\\\\\\\":{\\\\\\\"action\\\\\\\":\\\\\\\"open_url\\\\\\\",\\\\\\\"value\\\\\\\":\\\\\\\"http://gamemode4.wikia.com/wiki/Thread:18519#10\\\\\\\"}}]\\\"}}\",Text2:\"{\\\"text\\\":\\\"Regrowing Saplings\\\"}\",Text3:\"{\\\"text\\\":\\\"Click for info\\\"}\"}"},{id:MinecartCommandBlock,Command:kill @e[type=MinecartCommandBlock,r=1]}]}