Introduction

One of the problems that affect forage production in the Laguna Region is the low soil fertility, provoked by their overexploitation (^{Salazar et al., 2007}). In order to combat this, the incorporation of organic fertilizers (AO for its acronym in Spanish) is essential, as it is unavoidable that organic matter, besides being the basic support for soil life, can define its productive potential (^{Sánchez et al., 2011}). Among the products used as raw material to generate AO are different manures, crop residues and urban materials prunings, seaweed, among other residues, which are not contaminated (^{Sánchez et al., 2011}), in addition to from these materials they have also been generated extracts or liquid fertilizers, which are used both as a nutritional alternative for soils and plants and for managing crop diseases (^{Canales, 1999}; ^{Zermeño et al., 2015}). As already described, and as being of interest producer knowing the effect of Acadian fertilizers Soil and Foliar Acadian (Stimplex) [Dow AgroSciences of Mexico, SA. of CV.^®], obtained from seaweed extracts, aimed to assess the effect of these AO, seeking to meet the nutritional requirements of the crop on the yield and quality of forage maize.

The experimental batch 20 ha or located in smallholdings in stable krona (approx. 4 km of the road “La Partida-Granada” municipally of Matamoros, Coahuila, within Lagunera (101° 41’ and 104° 61’ west longitude, and 24° 59’ and 26° 53’ north latitude). The study was conducted in April-August 2015. The area, whose previous crop was alfalfa, was fallowed and then three steps were performed dray. The planting hybrid 2A120 (Dow AgroSciencesd and Mexico, SA. CV.^®) with 99% purity, was done dry, 20 April 2015, at the rate of 6 to 7 seeds 1 m linear (60 000 plants ha^-1). Four days after the 1^st irrigation was metered in total 4 irrigations, distributed every 28 to 30 days, with a total sheet 80 cm were applied.

The treatments were: T1= Acadian soil [seed inoculation (100 mL 20 kg^-1 seed) and soil application 2^nd and 3^th irrigation (0.5 L ha^-1 irrigation^-1)] + Stimplex foliar [two foliar applications (where the plants had 4 to 6 true leaves) at 0.5 L ha^-1] and T2= witness commercial [A sowing dose 50-80-00 was applied using ((NH₄)₂SO₄ and monoammonium phosphate (MAP) and dose 140-00-00 (NPK) to 1^st irrigation with urea]. The Acadian Acadian Soil and foliar (Stimplex) are ones formulation designed to apply at soil (PH 7.8-8.2) and to the foliage (pH 3.6-4.2), respectively, and have OMRI and BSC certification.

During the development of culture they were evaluated: emergency (E), at 15, 19 and 24 days after planting (dds) the number of plants born per 6 m, root development (DR) was measured 30 days after 1^st irrigation using a “lagunera” shovel, 16 plants which were removed waste soil were removed, placed in ice buckets to avoid dehydration, were transferred to the laboratory were weighed, using the vegetative part below the crown, in an analytical balance (Type 1501, Sartorius^®) for plant vigor (VP) scale force and Kortleve ^{Huisman (1994)} , who suggest evaluations at 7, 14 and 21 after germination was used, using the scale “vigor rating” 0 to 9; height plant (AP), was recorded at 15, 30, 60 and 90 days 1^st watering, using a flexible tape, it was placed at ground level and the value was recorded to the development of the last leaf center apex of growth, ren dure crop, depending on the production of green fodder (FV) and dry matter (MS) per hectare, at 90 they got green samples, representing each treatment and replicate, and dried in an oven of forced air circulation at 60 °C for 72 h.

An experimental block design was used with two treatments randomly and 16 repetitions. These variables were subjected to Andevas and mean separation with DMS_5%, Test complemented by descriptive statistics to obtain the standard error and ranges of data results.

In the Table 1 shows the results of emergency at 15, 19 and 24 dds. In this can be seen only is recorded on significant differences (p≤ 0.05), at 19 and 24 days after planting, due to the effect of T1, exceeding 2.98 and 4.61% emergency with respect to T2. Applying AO derivatives seaweed extracts, it is beneficial in producing silage maize, since the emergence of wheat (Triticum aestivum L.) and maize evaluated 20 dds decreases considerably to increase the fertilization nitrogen (^{Kitchen and Westfall, 1990}). The results were far outweighed by those reported by ^{Sánchez et al. (2014)} who when performing the inoculation of maize seed with Azotobacter spp., Burkhodelia spp., more nitrogenous fertilizer, 50%, recorded at 11 dds, 95% emergency, while the control, uninoculated and nitrogenous fertilizer 100%, 85% it obtained emergency. Furthermore, emergency values obtained 24 days after planting were similar to those reported by ^{Clau et al. (2013)} who observed no significant differences between test and recorded 90% emergence, at 30 dds, soybean cultivation in double inoculation Bradyrhizobium-mycorrhizae and use of herbal seed.

Literales diferentes dentro del mismo día de tratamiento difieren estadísticamente (p≤ 0.05).

Table 1 Emergency assessment in forage maize developed with organic fertilizers and commercial control producer, S-S cycle, 2015. 

For VP, which is required for both a suitable facility and for a successful development of maize (^{Oskouei et al., 2014}) showed that plants T2 were more vigorous in the first 15 dap, and in turn the plants which they were fertilized with AO (Acadian soil and foliar Stimplex) had spent more vigorously as experimental development (Table 2). It is or may be due to the AO, although having a low concentration of nutrients, are characterized by slow release, besides having residual stocks and improving effects on soil properties receiving incorporation (^{Fortis et al., 2009}).

Literales diferentes en líneas difieren significativamente; ns= no significativa.

Table 2 Plant vigor (± standard error) silage maize, developed with organic fertilizers and commercial control producer, S-S cycle, 2015. 

In the Table 3, results are presented for the AP. It is noteworthy that the first evaluation was scheduled for April 30, in which no plant emergence was recorded, above was because the producer made planting dry and apply or the 1st watering between 3 to 4 dds. In the same Table 3 shows that only significant differences (p≤ 0.05) at 39 dds, with a value of 58.56 ±2.36 cm at T1, while at T2 it was 51.03 ±1.37 cm, with the minimum and maximum ranges being 40 and 76 cm, respectively.

Literales diferentes en líneas son estadísticamente diferentes. ns= no significativa.

Table 3 Evaluation results of plant height of forage maize crop developed with AO and commercial control of the producer, S-S Cycle, 2015. 

The AP registered, 2.59 m 90 days, for forage corn fertilized with seaweed extracts, slightly lower result (11.3%) the average value reported by ^{Olague et al. (2006)}, for this crop fertilized with 100 t ha^-1 cattle manure, soil incorporated three months before sowing and planting 62-00-00 dose and 50-00-00 (NPK) in system sub-surface irrigation, with three separations irrigation belt (80, 90 and 100 cm), developed in a similar cycle, S-S and within the same agricultural region. For his part Salazar et al. (2010) reported an average forage maize AP 2.58 m, as a result of application of cattle dung for six years in doses of 0, 40, 80, 120 and 160 t ha^-1. This allows emphasizing that the AO used favored AP corn without applying synthetic fertilizers.

Results for DR, 30 days after 1st irrigation, are shown in Table 4, the Andeva recorded significant differences (p≤ 0.05) effect of treatment, the greater root weight observed in T1, with 27.40 ±2.77 g, beating DR T2, 42.34%. DR for the minimum range and maximum observed were 13 and 48.3 and 10.8 and 28.7 for T1 and T2, respectively. The DR results coincide with those obtained by ^{Khan et al. (2012)} they determined that fertilization extract of [Ascophyllum nodosum (L.) Le Jolis] (EAN) stimulates both formation of nodules on the roots and the growth of alfalfa and suggest that it may contain compounds that promote the legume-rhizobia symbiotic relationship.

DR= desarrollo radicular; FV= forraje verde; MS= materia seca. Literales diferentes en columnas difieren estadísticamente (p≤ 0.05).

Table 4 Evaluation of root development, and dry matter forage corn organic fertilization and commercial control of the producer cycle S-S, 2015. 

For variable RC shown in Table 4 that the effect of the AO used in the T1 favored l as significant (p≤ 0.05) between treatments. The average corn FV with AO -Acadian soil and foliar Stimplex- was 59 402. 063 kg ha ^-1, registering a difference of 4 935.91 kg ha ^-1 compared to T2. In studies with AO in Laguna region by ^{Fortis et al. (2009)} determined that the ANDEVA showed that FV was significant at 1.3%, indicating that at least one of the four treatments evaluated generated higher returns. The FV average obtained was 51 000 kg ha^-1 and a CV of 17.28%. The comparing means, it was determined that the application of the vermicompost is obtains 64 000 kg ha^-1, and with biocompost 56 000 kg ha^-1, both values very similarly at performance to that obtained of 59 402.063 kg ha^-1 FV of corn.

In Table 4 results are presented for MS, in the can be seen to be recorded on significant differences (p≤ 0.05) due to the effect of the AO Acadian soil and foliar Stimplex with 20 098.44 kg ha^-1 for T1, obtaining a difference of 1 670.04 kg ha^-1 compared to T2. The amount of corn MS obtained as in the case of FV, exceeded at least 40.23 and 32.31% to the average value for this variable reportad or by ^{Fortis et al. (2009)}; ^{Yescas et al. (2015)}, in the first case as a result of the incorporation of vermicompost and biocompost and in the second case due to the application of synthetic fertilizers, both works developed same agricultural region. The increase in production, both FV and the MS corn, it can occur that AO, not only results in the benefit of the properties of the soil, but are also a natural source that releases elements nutritious mind gradually during cultivation phenological cycle where these products are incorporated (^{Fortis et al., 2009}).

Conclusions

The application of AO, Acadian Soil and Acadian Foliar (Stimplex), obtained from extracts of seaweed, during the development of forage maize, besides covering their nutritional requirements, caused that their plants managed to reflect greater vigor and greater root weight, favoring also the obtaining of higher yields of FV and MS, the previous one without application of synthetic fertilizers.