Alessandra Aparecida Giacomini

Combinations between crop intercropping and forage production in a no-tillage system are not well established for environments under low water retention and soil fertility conditions. Our study aimed to evaluate the potential interactions between soybean-grass intercropping with residual nitrogen in a no-tillage system. The experimental design was a randomized block with four replications in a subdivided plot scheme. The main plots in the summer season were: 1) soybean monoculture; 2) soybean - Aruana Guinea grass (Megathyrsus maximus cv. Aruana) intercropping, and 3) soybean - Congo grass (Urochloa ruziziensis cv. Comum) intercropping. The subplots were the nitrogen rates of 0, 50, 100, and 150 kg ha-1, applied as side-dressing in maize and grasses during the autumn-winter season. Here, the results of the summer seasons are shown. To do so, the parameters evaluated were soybean agronomic traits, dry biomass production, and macronutrient concentrations of plants intercropped. The main effects and interactions were studied. Our findings showed that soybean-Aruana Guinea grass intercropping is an alternative to no-tillage system implementation. Moreover, residual nitrogen from the autumn-winter season directly interfered with the dry biomass production of grasses intercropped with soybeans in the summer season. In short, the systems studied seem suitable for implementing a no-tillage system, which aims to neutralize degraded pastures and produce forage for ensilage. Despite the changes in macronutrient concentrations within the intercropping system and residual nitrogen, and among intercropped crops over the years, Congo grass intercropped with soybeans in the summer season showed great capacity for phosphorus, potassium, and magnesium cycling.

Changes in sward height of pastures managed by continuous grazing according to climatic seasonality may alter tillering and forage production. In order to evaluate the feasibility of seasonal alteration in sward height of Marandu palisade grass pastures (Brachiaria brizantha (Hochst. ex A.Rich.) R.D. Webster; syn. Urochloa brizantha (A.Rich.) Stapf) under continuous grazing management, we studied two constant sward heights (15 cm and 30 cm), and one height that was initiated at 30 cm, reduced to 15 cm in June (dry and cold season) and returned to 30 cm in December (wet and hot season) (30–15–30 cm). Pastures managed at 30–15–30 cm had a greater tiller appearance rate (22 tillers/100 tillers.30 days) than those maintained at 15 cm and 30 cm (16 and 17 tillers/100 tillers.30 days, respectively). In the 30–15–30 cm pastures, a lower accumulation rate of dead material was observed during the dry and cold season (June–August), which resulted in a higher leaf and lower dead material accumulation rate during the second growth season (wet and hot season, December–January). Planned reduction in sward height during the cold season can be used safely because it permits better seasonal distribution and utilisation of forage production without compromising the stability of Marandu palisade grass pastures.

The experiment was developed at the Instituto de Zootecnia in Nova Odessa-SP. It was designed to evaluate forage mass, forage legumes ratio in the available forage mass and the transfer potential of the nitrogen fixed by the forage legumes to Aruana Guineagrass pasture grazed by lambs under intermittent grazing. The treatments consisted of the introduction of four accessions of forage legumes in the pasture of Megathyrsus maximum cv. Aruana and a treatment of Aruana Guineagrass pasture (without legumes), totalling five treatments. The Aruana Guineagrass pasture was established five years ago. The forage legumes treatments were: Neonotonia wightii NO 253 (Perennial soy NO 253), Neonotonia wightii NO 2348 (Perennial soy NO 2348), Macrotyloma axillare NO 279 (Macrotyloma legume) and Calopogonium mucunoides NO 1194 (Calapo legume). The experimental design was made up of random blocks with three replicates. The Calapo legume showed the lowest mean forage mass in the three seasons (400 kg/ha). The mean forage mass of the Perennial soy NO 253, Perennial soy NO 2348 and Macrotyloma legume did not show significant differences in the three seasons. Furthermore, the Calapo legume ratio in the pasture was the lowest in the total forage mass (13%) among the intercropped forage legumes (31.9% at 43.2%). Perennial soy NO 253, Perennial soy NO 2348 and Macrotyloma legume showed suitable ratio in the forage mass when intercropped with Aruana Guineagrass. These forage legumes also promoted the highest crude protein content in the Aruana Guineagrass. Thus, it is possible to advise the introduction of Perennial soy NO253, Perennial soy NO2548 or Macrotyloma legume in established Aruana grass pasture.

The present study aimed to assess the effects of combinations of doses of phosphorus and calcium on the yield characteristics of Macrotyloma axillare access NO 279 (family Fabaceae) in a Red-Yellow Argisol with average P level (24 mg dm-3). The experiment was carried out in greenhouse in Nova Odessa/SP, Brazil, from August to December 2015. A 52 fractional factorial design with 13 combinations for doses of phosphorus and calcium in mg dm-3: 0-0; 0-40; 0-80; 15-20; 15-60; 30-0; 30-40; 30-80; 45-20; 45-60; 60-0; 60-40; 60-80, in a randomized complete block design with four replications. Two cuttings were made on the plants. The phosphorus x calcium interaction and the isolated doses of calcium were not significant for the parameters assessed. The production of dry biomass of the aerial part, the leaf area, the number of leaves and the number of branches of Macrotyloma showed significant responses to the isolated doses of phosphorus applied in the primary growth. In the secondary growth, only the number of branches and the dry biomass production of the dead material responded to the doses of phosphorus. Phosphorus was a modulator of dry biomass production of roots and of the production of nodules and the number of nodules of macrotyloma. The content of calcium present in the soil, together with the increase of the value of base saturation to 50%, was sufficient for the establishment and growth of the legume. Therefore, a supplemental dose of this nutrient was not required.

The corn-grass intercropping system began to be used in the dry season, as it provides increased straw production for the no-tillage system. However, corn and grass are plants demanding in nitrogen. The corn cultivated in the dry season is called out-of-season corn in Brazil. The objective of this study was to evaluate the productivity and nutrients concentrations of out-of-season corn and Congo-grass intercropped in the no-tillage system, as a function of the nitrogen rates applied in sidedressing. The treatments were four nitrogen rates, 0, 30, 60 and 90 kg ha⁻¹. The experimental design was randomised complete blocks with four replicates. The experimental period corresponded to the harvests of 2015 and 2016. There were evaluated: corn grain yield, dry mass production and nutrient concentration in the shoots of the plants intercropped. The evaluations were carried out at the physiological maturity stage of the corn and at the time of desiccation of the grass. Nitrogen increased grain yield and dry mass production of the plants intercropped. Nitrogen maximised the magnesium concentration in out-of-season corn and the nitrogen, calcium, magnesium and sulphur concentrations in Congo grass. Excess nitrogen promoted reduction of the phosphorus in the Corn-Congo grass intercropping system in the dry season.

Intercropping is a method for straw production and maintenance during the dry season in no-tillage systems. Among the crops used for intercropping are corn and grasses. However, nitrogen can interfere with the production capacity of these plants. The objective of this study was to evaluate the macronutrient accumulations and efficiency values of out-of-season corn and Congo grass intercropped under a no-tillage system as a function of the nitrogen fertilisation applied by side dressing. The experimental design was a randomised complete block with four replicates of four nitrogen application rates: 0, 30, 60 and 90 kg ha-1. The evaluations were carried out when the corn was physiologically mature. The phosphorus and potassium accumulation and nitrogen utilisation efficiency of the out-of-season corn did not respond to the nitrogen rates. The nitrogen recovery efficiency and the nitrogen to biomass conversion efficiency of the Congo grass also did not respond to nitrogen application rates. Nitrogen fertilisation as side dressing in the rows of the out-of-season corn and Congo grass intercropping improves the nutrient cycling in the no-tillage system. Side dressing fertilisation with nitrogen improves the agronomic efficiency and physiological efficiency of the out-of-season corn and Congo grass intercropping under a no-tillage system.

The objective of this study was to evaluate milk production and ingestive behavior of Holstein cows and the structural characteristics of Mulato II, a hybrid Brachiaria grass CIAT 36087 (B. ruziziensis × B. decumbens × B. brizantha), and Marandu (Brachiaria brizantha cv. Marandu) pastures under rotational stocking. The experiment was conducted from December 2011 to April 2012 after 10 months of adaptation to the grazing management objectives (25 cm pre-grazing height and 15-20 cm post-grazing height). An area of 4 ha was divided into 28 paddocks: 14 with Mulato II pasture and 14 with Marandu pasture. The treatments consisted of the two grasses and a completely randomized design of the grazing variables with six repetitions each (paddock of evaluation) was used. For the animal variables, a randomized matched pairs design of 20 Holstein cows forming 10 blocks of two animals with similar production each was used. The forage mass or accumulation rate did not differ between grasses. Mulato II pastures had a higher tiller population density (822 tillers m⁻²) and crude protein content (143.5 g kg⁻¹) than Marandu pastures (636 tillers m⁻² and 130.3 g kg⁻¹ crude protein). Cows kept on Mulato II exhibited shorter nighttime grazing activity (234 and 246 min in summer and autumn, respectively) than animals kept on Marandu (273 and 394 min, respectively). The average milk yield during the experimental period was higher for Mulato II (15.3 kg cow⁻¹ day⁻¹) compared with Marandu (14.3 kg cow⁻¹ day⁻¹). Both grasses have potential to be used in milk production systems for the grazing management objectives evaluated.

The response of legumes to the supply of either phosphorus (P) or calcium (Ca) alone has been extensively investigated but no prior studies have evaluated their combinations in the perennial legume Macrotyloma axillare (Macrotyloma legume). This study assessed the mineral composition of Macrotyloma legume in response to the combined application of P and Ca in an Ultisol. The experiment was conducted in a greenhouse in Nova Odessa city, São Paulo, Brazil. Five rates of P and Ca, respectively, were combined in a 52 incomplete fractional factorial design. Thus, the treatments consisted of 13 P and Ca combination rates (respectively, in mg dm−3): 0‒0, 0‒40, 0‒80, 15‒20, 15‒60, 30‒0, 30‒40, 30‒80, 45‒20, 45‒60, 60‒0, 60‒40 and 60‒80 arranged in a randomised block design with four replications. Mineral composition was evaluated after two harvests (53 d after sowing and 34 d after the first harvest). During the initial growth of the Macrotyloma legume, P × Ca interactions occurred. The P supply antagonistically ...

Sustainable models of animal production constantly seek for ways to pasture production with inputs reduction. In this context, the introduction of forage legumes in the pasture system is fundamental to fix nitrogen from the atmosphere and supply it to grasses, increasing its production and persistence, enhancing animal nutrition as it grazes, at the same time. Still, the use of plant mixes in the system brings further benefits to it, such as better utilization of fertilizers as well as enhances the nutrient cycle and soil coverage. However, there are still many gaps in our knowledge regarding intercropping legumes and grasses, especially the use of tropical legumes. The purpose of this review is compiles data about forage legumes as well as analyses them to find new tendencies and gaps on the knowledge to shed some lights on researches in this area. We also expect that this review will help researchers and producers to understand the role of forage legumes in a pasture system and that there will be an increase in its utilization worldwide, especially in the tropics, where nitrogen is easily leached and lost from the pastures. With emphasis on description of promising tropical legumes but still little used Arachis pintoi, Macrotyloma and Neonotonia whightii. Key words: Arachis pintoi, grass, Macrotyloma axillare, mixed pasture, Neonotonia wightii.