Agriculture and livestock integration is a sustainable practice that improves both crop yield and pasture recuperation/formation. However, to achieve success it is important to identify crop cultivars more adapted to intercropping with grasses. Th erefore, the objective was to evaluate nutrient concentration and grain yield of soybean [Glycine max (L.) Merr.] cultivars with diff erent life cycles as aff ected by palisadegrass [Brachiaria brizantha (Hochst. ex A. Rich) Stapf] intercropped in the same furrow at diff erent depths, in a no-till system, as well as dry matter production and protein concentration of palisadegrass pasture. Experiments were performed during two growing seasons, on a Typic Haplorthox, at Botucatu, São Paulo State, Brazil. Th e experimental design was a randomized block, arranged in a 2 × 4 factorial scheme, with six replications. Treatments consisted of two cropping systems (sole cropped soybean; soybean and palisadegrass intercropped) and four soybean cultivars (super-early cycle [Monsoy 6101], early cycle [Embrapa 48], normal cycle [BRS 133], and late cycle [Emgopa 313]). Life cycle duration of the soybean had a marked eff ect, and only early cycle soybean were successful intercrops. Intercropping palisadegrass with super-early or early soybean cultivars were viable options to crop-livestock integration, because they did not aff ect both soybean or palisadegrass yield. In addition, with these cultivars, it was possible to cultivate grain and then aft erward more time for cattle (Bos taurus and Bos indicus) grazing in the same area, providing greater revenue compared to sole soybean cropped or in the intercropping with longer cycle cultivars.

Intercropping corn (Zea mays L.) with forages, such as palisadegrass {Urochloa brizantha (Hochst. ex A. Rich.) R. D. Webster [syn. Brachiaria brizantha (Hochst. ex A. Rich.) Stapf]} or guineagrass [Megathyrsus maximus (Jacq.) B. K. Simon & S. W. L. Jacobs (syn. Panicum maximum Jacq.)], provides large amounts of biomass for use as straw in no‐tillage systems or as pasture. However, it is important to evaluate what time these forages have to be sown into corn systems to avoid reductions in both corn and forage production. This study, conducted for three growing seasons at Botucatu, Brazil, evaluated nutrient concentration and yield of corn as affected by time of forage intercropped as well as forage's dry matter production. Our data showed that intercropping systems did not reduce leaf nutrient concentrations and grain yield of corn in relation to sole corn. The simultaneous intercropping of corn and guineagrass resulted in the lowest plant population (51,200 plant ha−1), number of ears per plant (1.0), and, consequently, the lowest corn grain yield (9801 kg ha−1). Guineagrass seeded at the time of corn fertilizer topdressing resulted in the highest plant population (59,400 plants ha−1), number of ears per plant (1.2), and corn grain yield (12,077 kg ha−1). Forage production was highest when intercrop was done simultaneously. Palisadegrass could be intercropped with corn both simultaneously or at topdressing fertilization stage. In contrast, it is recommended that guineagrass should only be intercropped with corn at topdressing fertilization.

Resumo -O objetivo deste trabalho foi avaliar a influência, sobre a produtividade de grãos, da modalidade de consorciação da Brachiaria brizantha cultivar Marandu com a cultura do milho, em dois espaçamentos de semeadura, em sistema plantio direto. O experimento foi instalado em campo, em e 2003, Botucatu, SP. O delineamento experimental foi o de blocos ao acaso, em esquema fatorial simples 2x4, com quatro repetições. Os tratamentos foram dois espaçamentos entre linhas de milho (0,45 e 0,90 m) e quatro modalidades de cultivo: milho solteiro; milho com braquiária na linha de semeadura; milho com braquiária na entrelinha; e milho com braquiária simultaneamente na linha e na entrelinha. A modalidade de consórcio e o espaçamento utilizado não comprometem a absorção de nitrogênio, nem pelo milho nem pela forrageira. A produtividade de grãos de milho, no espaçamento de 0,45 m, é menor com o consórcio da braquiária na linha e entrelinha simultaneamente. Conforme o ano agrícola, a produtividade de grãos é maior no espaçamento reduzido, quando consorciado com braquiária, independentemente da modalidade.Termos para indexação: Zea mays, sistema de cultivo, integração lavoura-pecuária, consórcio. Corn yield, spacing and intercropping modalities with Brachiaria brizantha in no-tillage systemAbstract -The objective of this research was to evaluate the effects on corn yield of different modes of corn intercropping with Brachiaria brizantha cv. Marandu. The experiment was carried out in field conditions, in , in Botucatu, SP, Brazil. The experimental design was the randomized complete block, as a factorial 2x4, with four replications. The treatments were two row spacings of corn (0.45 and 0.90 m) and four intercropping modalities: single corn; corn intercropped with B. brizantha in the row of sowing; corn intercropped with B. brizantha in space between two rows; and corn intercropped simultaneously with B. brizantha in the row and in the inter-row. The consortium modalities and the spacing used did not damage nitrogen absorption, neither for the corn nor the forage. Corn grains productivity in 0.45 m row spacing was lower with the row and inter-row Brachiaria consortium. Depending on agricultural year, grain yield is greater in the reduced row spacing, when intercropping with Brachiaria, independently of the modality.

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In tropical regions with dry winters, low plant biomass accumulation during the period between spring–summer crop cultivations can negatively impact soil resources and make the no‐till (NT) system unsustainable. Incorporating palisadegrass [Urochloa brizantha (Hochst. Ex A. Rich.) R.D. Webster] [syn. Brachiaria brizantha (Hochst. Ex A. Rich) Stapf] in traditional grain production areas could improve soil quality for subsequent crops and lead to positive effects on grain yield. The objective of this study was to evaluate the effects of growing palisadegrass on soil fertility, plant nutrition, and grain yield of subsequent cash crops in a tropical region. The experiment was performed in southeastern Brazil in plots that were grown for two consecutive growing seasons (2002–2003 and 2003–2004) with either monocropped corn (Zea mays L.) or corn intercropped with palisadegrass. An initial evaluation of soil fertility was performed in November 2004 when the land was either fallow (following monocropped corn) or covered by palisadegrass (intercropped areas). After the preceding treatments, the following crops were cultivated: soybean [Glycine max (L.) Merr.] during the 2004–2005 and 2005–2006 spring–summer, white oat (Avena sativa L.) during the 2005 and 2006 fall–winter, and corn during the 2006–2007 spring–summer. Intercropping palisadegrass with corn increased the soil fertility compared to monocropped corn. Soybean, white oat, and corn all had higher leaf macronutrient concentrations and grain yields in previously intercropped areas than in monocropped areas. Therefore, the periodic, short‐term incorporation of a perennial forage grass, such as palisadegrass, as a cover crop is recommended to increase grain production and to improve the soil fertility of grain‐production areas.

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Intercropping corn (Zea mays L.) with palisadegrass [Brachiaria brizantha (Hochst. ex A. Rich) Stapf] can result in high amounts of residue and improve nutrient cycling. Long‐season corn hybrids will live longer, competing with palisadegrass, which may reduce both corn and forage biomass yields. This study, conducted in the state of São Paulo, Brazil, had the objective of evaluating nutrient concentration and yield of corn hybrids with different maturity ratings as affected by intercropped palisadegrass as well as forage dry matter production. The experimental design was randomized blocks with a factorial arrangement of eight treatments consisting of two cropping systems (corn alone and intercropped with palisadegrass) and four corn hybrids (105‐, 121‐, 132, and 144‐d relative maturity). Compared with corn grown alone, intercropping treatments resulted in corn grain yields of 107% (105‐d hybrid) to 71.7% (144‐d hybrid). In the corn‐alone system, the 132‐ and 144‐d corn hybrids provided the highest corn yields (9581 and 9606 kg ha−1, respectively). Corn yield was similar between the single‐crop and intercrop systems when using 105‐, 121‐, and 132‐d hybrids. Intercropping with the 144‐d hybrid reduced forage production (6619 kg ha−1) and quality of palisadegrass (86 g kg−1 of crude protein) compared with the other hybrids. The intercropping system with the 132‐d hybrid allowed both the highest corn grain (8860 kg ha−1) and palisadegrass (8256 kg ha−1) yields. Therefore, intercropping palisadegrass with the earlier (105‐, 121‐, and 132‐d) corn hybrids is a viable option for crop–livestock integration because it did not affect either corn or palisadegrass yield.

Intercropping of maize (Zea mays L.) with perennial forage, such as palisade grass [Brachiaria brizantha (Hochst. ex A. Rich) Stapf], provides large amounts of biomass that can be used as straw for no-tillage systems or as pasture for animal grazing. In addition, the use of narrow row spacing may increase maize grain yield. However, it is important to evaluate intercrops at different row spacing to avoid reductions in both maize and forage biomass production. The objectives of this field experiment during two growing seasons in Brazil were as follows: (1) to evaluate the influence of intercropping and row spacing on maize yield, leaf nutrient concentration, and plant population and development; and (2) to assess the influence of row spacing on palisade grass herbage mass and leaf nutrient concentration. The experimental design was a randomised complete block design in a 2 × 2 factorial scheme, with eight replications. The treatments comprised two row spacing distances (0.45 and 0.90 m) and two crop management types (maize monoculture and intercropped with palisade grass). The nutrient concentrations in the leaves of the maize plants were in the ideal range for this crop under all conditions studied. Plant height, height of first ear, and number of grains per ear were higher with the narrow row spacing. Maize grain yield was similar in both crop management types (10 301 and 9745 kg ha–1 for monoculture maize and intercropped, respectively). However, maize grain yield at the narrow row spacing was higher than that obtained with the wide row spacing (9948 v. 8905 kg ha–1). In contrast, row spacing did not affect the nutrient level or quality (crude protein concentration) of palisade grass. The amount of dry matter (DM) from palisade grass was lower at maize harvesting (4.7 Mg ha–1) and 90 days after harvesting (6.9 Mg ha–1) under narrow spacing. However, the amount of DM was similar at both row spacings at 120 days after maize harvesting (9.2 Mg ha–1). When there is no problem with water and nutrient availability, the use of maize and palisade grass intercropping under both row spacing conditions (0.45 and 0.90 m) provides an option for the production of forage DM without reducing the maize grain yield.