No-till farming means the way of growing crops from year to year without disturbing the soil through tillage. No-till is an agricultural technique which increases the amount of water and nutrients in the soil and decreases erosion. It increases the amount and variety of life in and on the soil (1).
According to FAO in 1999 no-tillage farming was adopted on about 45 million ha in the world, growing to 72 mln ha in 2003 and to 111 mln ha in 2009, corresponding to an growth rate of 6 mln ha per annum. Fastest adoption rates have been experienced in South America where some countries are using no-tillage farming on about 70% of the total cultivated area (2).
The idea of modern no-till started in the 1940s with Edward Faulkner, but it wasn’t until the development of several chemicals after WWII that various researchers and farmers started to try out the idea. The first adopters of no-till include Klingman (North Carolina), Edward Faulkner, L.A. Porter (New Zealand), Harry and Lawrence Young (Herndon, Kentucky), the Instituto de Pesquisas Agropecuarias Meridional (1971 in Brazil) with Herbert Bartz (3).
No-till supports the principles of minimum-tillage by reducing tillage to only one operation: opening the soil for the seed at planting time. No-till has been adopted widely for corn, soybeans, and cowpeas. For example, corn can be planted in the stubble from the previous crop or in a mulch of other cover crops which have been killed by a herbicide. The practice is spreading to other crops, including small grains. Because it eliminates conventional tillage operations, no-till farming saves on energy and labor costs. Switching from conventional to no-till, in fact, can save up to 75 % of the energy used for standard tillage (4).
No-tillage technologies have a great potential to increase organic matter content of the soil and sequester carbon while building and maintaining good soil structure and health compared to intensive tillage systems that does exactly the opposite. The no-till system is very effective to increase soil water infiltration, to reduce evaporation from soil and also to reduce water run-off. The water availability for crops is increased, offering the opportunity to improve general soil functioning and crop performance. The principles are equally useful for both rain-feed or irrigated cropping condition (5).
Advantages of minimum and no-till systems are:
less energy and labor are required for tillage and planting;
energy and labor in the total production process are reduced;
fewer farm machinery is needed;
water runoff is reduced, which is beneficial in two ways: more water is available for the crop and soil erosion is reduced;
crop yields are equal to or better than under conventional tillage.
planting times are more flexible.
Disadvantages of minimum and no-till systems are:
specialized planting equipment is needed, although there are the alternative options of hand labor and modified conventional planters;
herbicides must be used often and with accuracy;
sometimes, it is difficult to cover the seed in a no-till situation;
applying herbicide and fertilizer is difficult due to the absence of rows or lines to follow;
if the ground is hard due to lack of rain, the planter may not be able to penetrate the soil (6).