John Deere 4455, Summers rock picker, North Dakota 2

A stone picker (or rock picker) is an implement to sieve through the top layer of

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

to separate and collect

rocks In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's ...

and soil debris from good topsoil. It is usually

tractor A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a trailer or machinery such as that used in agriculture, mining or construction. Most comm ...

-pulled. A stone picker is similar in function to a rock windrower (rock rake); a stone picker generally digs to greater depths to remove stones and rocks. Stone pickers are used in farming and landscaping, where stones need to be removed from the soil and ground surface to prevent damage to other farm machinery (such as hay balers, combines, and

mower A mower is a person or machine that cuts (mows) grass or other plants that grow on the ground. Usually mowing is distinguished from reaping, which uses similar implements, but is the traditional term for harvesting grain crops, e.g. with reapers ...

s), improve the soil for crop production, or improve the appearance of the ground surface in preparation for a lawn or a golf course. Surface stones and large rocks often left from plowing can damage a hay bailer, the header or reciprocating knives on a combine, and blades on a

rotary mower Rotary may refer to: General * Rotary motion Engineering and technology * Rotary dial, a rotating telephone dial * Rotary engine (disambiguation), multiple types of engines called "rotary" * Rotary latch * Rotary milking shed, a type of milking ...

. Land with rock instead of fine soil are often less useful for crops. Thus, removing stones from the soil also ensures a more consistent yield. Additionally, using stone pickers is particularly useful for crops forming tubers (such as potatoes) in the ground. A stone picker has digging teeth, a conveyor system, a sieve or screen, and a stone bin. The digging teeth are at the leading edge of the stone picker and removes soil, which is placed on the conveyor system. If the sieve is not combined with the conveyor system, the conveyor system transports the stones and large rocks to a bin or hopper for periodic dumping. Some stone pickers use a large tractor, generally over 100

horsepower Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are th ...

, equipped with hydraulics and

power take-off A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machine. Most commonly, it is a s ...

driven mechanisms. PTO pump driven equipment can use 60 horsepower tractors. The tractor's hydraulics control the depth to which the stone picker digs to excavate soil material; whereas, the PTO controls the movement of the conveyor and picking system.

External links

*{{commonscatinline, Rock pickers, lcfirst=yes Agricultural machinery