Successful livestock farming begins with choosing a forage suitable for the livestock production system (category and productivity goals), technological conditions (equipment, workers and investments) and the analysis of soil and climate (local weather, as well as chemical and physical properties of the soil). The acquisition of inspected and certified seed is also important. The seeds must be within the legal standards for purity and the presence of noxious weed seeds.
Once the choice of forage is made, certain steps must be followed to obtain a well-established and productive pasture:
A certified laboratory should do the soil analysis to determine the need for liming (to correct soil acidity) and fertilization. Follow these steps to collect soil samples:
1) Divide the area to be tested into uniform sections
According to the following criteria:
- Visual criteria: topography or slope, soil color, type or texture of the soil, drainage and vegetation cover.
- Informational Criteria: history of liming and fertilization, production in previous years and the presence of pests/diseases in the last crop.
The extent of the sample area may vary according to its homogeneity, but it is best not to exceed 50 ha.
A screw auger, soil auger, Dutch auger, metal probe or mattock or spade can be used to take a soil sample. If using a mattock or spade, carefully dig the hole to prevent any unwanted soil from mixing with the soil sample. Once the hole is dug, cut vertical strips of soil from the sides and mix them to obtain a representative sample.
Zigzag your way across the test area randomly choosing places to collect samples. Avoid locations near termite mounds, anthills, feces or animal remains, as well as water and salt troughs.
Before taking a sample, remember to clear away leaves, twigs and other impurities that may contaminate the sample. The ideal sample is 0-20cm deep, since this is the layer of soil where plant roots develop and essential nutrients are most likely to be missing.
Twenty single samples should be taken from the same area and mixed in a clean bucket or plastic bag. This forms a representative composite sample.
3) Frequency of Testing
The frequency of soil testing varies according to the land use. Where there is only a perennial crop (i.e. pastures), the soil requires testing every 3-5 years. Land that produces 2 or 3 consecutive annual crops and undergoes intensive fertilization should be evaluated every 2 years.
4) Test Results
It is important to consult an agronomist about the results of soil testing. Their expertise guarantees a proper understanding of the results and the need for correction or fertilization.
Below are soil preparation guidelines for planting a new variety of forage or for recovering a rundown pasture where lime and conventional tillage is necessary:
1) Half of the corrective recommended by the soil tests and fertility level/land use should be spread before plowing and the other half after the first harrowing.
2) Liming 60-90 days before planting allows enough time for the lime to react in the soil.
3) The field should first be plowed or tilled to incorporate any remaining plant material into the soil and then harrowed. Harrowing breaks up clods, levels the surface and eliminates noxious weeds. As a general rule, harrowing a field twice is sufficient.
- Avoid excessive harrowing because it can cause soil pulverization.
- Terracing and plowing contour lines should be done after leveling and only where absolutely necessary. It is best to avoid terracing and contour lines where possible.
- If noxious weeds are abundant, weed control should be done manually or with herbicides. This prevents the weeds from germinating faster than the forage and eventually smothering it.
1) Sowing should be done during the rainy months (October to January).
2) Choose a method of seeding which will uniformly distribute the seeds over the area to be sown. If you opt to sow in rows or holes, spacing should be as close as possible (10 cm).
3) Always use inspected seeds which have a Cultural Value guarantee (CV%). These seeds are pure and free of noxious seeds (weeds). Using seeds with a CV% outside of the legal norms can hinder pasture establishment.
4) Pay attention to the sowing rate. This rate varies according to the type of grass and the Cultural Value of the seeds. Sowing insufficient seeds can also impede pasture establishment.
5) Immediately after seeding, take a flat roller over the area to increase soil-seed contact.