**4.1. Materials and methods**

(0.6 to 1.2 µg g-1 soil on 0-30 cm depth), could limit N mineralization [31], resulting in a poor

In experiment 2, burning was directed to reduce competition from existing grasses, since the way *A. pintoi* vegetative material was planted assured a close contact with the soil. However, burning, as well as fertilisation, did not show a clear positive trend either on

When only herbicide was applied in bands in experiment 2, pasture canopy height was not reduced, leading to reduced PH of *A. pintoi*. On the other hand, when the herbicide treated vegetation was burned, PH of *A. pintoi* was not impeded. Non-burned plots gave slightly taller *A. pintoi* plants than those burned. *A. pintoi* CIAT 18744 flowers less and produces a denser stolon mat than the other two accessions and it also has a vigorous initial growth, covering the soil more rapidly than the CIAT 17434 accession [32-33]. For this reason, a bet‐ ter behaviour during establishment, particularly with respect to COV and PN was expected from this cultivar. Nevertheless, in experiment 3, COV performance at the end of establish‐ ment was similar to that of CIAT 17434 (8.5% *vs.* 8.7%) and only slightly better than CIAT 18748 (7.5%). Then, the 3 accessions behaved similarly during establishment. Rates of plant emergence are considered to be good, as *A. pintoi* is a legume that can have a strong dor‐ mancy [34]. However, emergence (from 125 seeds originally planted/plot) of new branched plants/plot was not so bad, considering that these values ranged from 70% to 90% for three accessions. Therefore, there was low coverage but high number of new branched plants. This situation is common for *A. pintoi*, which is characterized by its slow establishment, as has been reported [6, 35-36]. Zero tillage failed to stimulate a rapid establishment of *A. pintoi* in these trials, the reproductive mechanisms of this species ensure that eventually it will es‐ tablish and encroach within the pasture. Our experience with this legume is that eventually it ends up to be the dominant species when associated with native pasture, Stargrass, or to both. A good strategy would be to establish *A. pintoi* in strips with reduced tillage at high density. This will result in a rapid establishment of a mixed sward in a minimum of time.

Neither fertilisation nor burning were successful in enhancing *A. pintoi* establishment; slashing did not improve establishment either. On the contrary, herbicides were effective and improved establishment over slashing. The best alternative to introduce *A. pintoi* into a native pasture is by reduced soil tillage in strips using, within the strips, 8 kg of pure live seed pods/ha; or 0.70 m between rows and 0.35 m between planting positions for veg‐

**4. Establishment of** *Arachis pintoi* **CIAT 17434 and** *Pueraria phaseoloides*

In the watershed Gulf of Mexico region, there is a highly seasonal pasture production due to climate variability. The main genera are components of *Paspalum*, *Panicum* and *Cynodon*

**CIAT 9900 using minimum tillage in Veracruz, Mexico**

legume performance.

62 Soil Fertility

COV or on PHT.

**3.5. Conclusions**

etative material.
