Cactus Forage Productivity Modelling Using PHYGROW Software in a Semiarid Environment

Plant growth modeling has been shown an increasing strategy to cope with the high demand for food supply, mainly in climate vulnerable areas, providing them to be used in agriculture worldwide. Concerning semiarid regions, the PHYGROW software has been promising to model plant growth, as cactus forage (‘Opuntia stricta’ cv. “Mexican elephant ear”) which was used in this study. Production data from 2017 and 2018 in Petrolina, Permambuco state, Brazil, with 12 replicates each year were considered. This region shows a very hot and dry climate and has an erratic and seasonal rainfall, which varies a lot in quantity, frequency and intensity from one year to another. After the PHYGROW software parameterization, we performed the generation of the synthetic series and, afterwards, we add the field data to calibration and validation. The results showed a high prediction capacity of PHYGROW software, even in such an erratic climate as Brazilian Semiarid, considering the model performed as calibrated. In 2017 and 2018, the observed cactus forage biomass were 1745 ± 505.83 and 2016 ± 584.58 kg DM ha-1 and the estimated data were 1795 and 2314 kg DM ha-1, respectively. This relatively high deviation suggests an opportunity to add more data, in order to get the model more accurate. Although there was a high difference in precipitation from 2017 to 2018 (166 and 301 mm, respectively), cactus forage was capable to offset this fluctuation, which makes it a strategic resource to reduces the biomass variation and stockpiling necessity on the farm level. This study also demonstrated the importance of modelling to help the farmer to cope with the weather and feed variation in climate vulnerable areas, allowing them to anticipate and adopt strategies to cope with drought more efficiently

Modelling \u3ci\u3eLeucaena\u3c/i\u3e Biomass Under Rainfed Production Systems of Semiarid Regions

The climatic variability of semiarid regions is the main source of uncertainties associated with forage and animal production, indicating a need for tools that accurately estimate forage production in order to construct a forage budgeting plan for livestock. This study simulated the biomass of Leucaena (Leucaena leucocephala) using the PHYGROW model in four locations located in Brazilian Semiarid. The work was carried out based on field data collected from 2019 to 2021. After sowing in 2018, leucaena was harvested when it reached 200 cm and to a target residual height of 70 cm. The biomass (fresh matter) was weighed, sampled and dried to obtain the total forage biomass (BFT) of each sample. The BFT was also estimated using the PHYGROW model, with field data being used to parameterize, calibrate and validate the model. The model performance, in turn, was evaluated based on the mean forecast error (BIAS %), root mean square error (RMSE) and Willmott index. Afterwards, a BFT time series was downloaded for each location, with the highest biomass simulated for each year being evaluated in the @Risk regarding their probability distribution. Thereafter, probability calculations of biomass production were performed, based on different levels of warranty in SigmaPlot software (11.0). The model underestimated the BFT collected in two locations and overestimated BFT in the others. The Weibull function was the best one to describe the data. Regarding biomass production under a 95% natural warranty, it was observed that leucaena showed low variation among locations (2240 ± 752 kg of DM ha-1 year-1 ). The PHYGROW model accurately predicted the leucaena BFT which, in turn, demonstrated significant adaptation potential to the various soil and climate conditions of Brazilian Semiarid. The use of probability analysis can contribute to forage planning, thus reducing the uncertainties related to climate variability, especially in rainfed production systems of dry areas

Modeling the water balance of a ruminant production system in the semi-arid region.

In the Brazilian semi-arid region, most cattle properties that use small dams as a source of water are unaware of the water balance of this system, which makes it difficult to plan and use this resource rationally. In this context, the objective was to demonstrate the impact of water consumption from a ruminant production system in a small reservoir. The water use model was developed using the Vensim PLE™ software for a hypothetical farm located in Petrolina, Pernambuco State, Brazil. The reservoir capacity and evaporation, infiltration and runoff rates were estimated from the literature and rainfall was estimated using the probability density function in the @RISK© software. The use of irrigation, water consumption of the family and farm, and water consumption by goats, sheep and cattle were estimated from the literature. In the horizon of 30 years, in only five of these the maximum capacity of the reservoir was reached. In the most demanding water scenarios, years are observed in which the reservoir dries up completely, making animal production unfeasible. Using the proposed model, it was possible to estimate, using real indicators, combinations to find the best way to use water, depending on the type of herd and the use of irrigation

Accumulation and export of nutrients in cactus pear cladodes (Opuntia ficus-indica) under different managements in the Brazilian Semiarid.

Abstract: The present study evaluated the accumulation and export of nutrients in cactus pear (Opuntia ficus-indica) cv. Gigante, fertilized with combinations of nitrogen (10, 70, 100, 130, and 190 kg ha -1 year -1 N) and phosphorus (10, 70, 100, 130, and 190 kg ha -1 year -1 P2O5) under annual and biennial harvests, in Quixadá and Tejuçuoca, using a split-plot randomized block design with four replications. In Quixadá, under annual and biennial harvests, the following orders of accumulation of macronutrients (in kg ha -1 year -1) were found, respectively: K (98.8) > Ca (87.2) > N (46.7) > Mg (26.8) > S (18.4) > P (2.04) and Ca (33.5) > K (31.1) > S (18.6) > N (12.9) > Mg (10.5) > P (0.81). In Tejuçuoca, under annual and biennial harvests, the orders of accumulation of macronutrients were, respectively: K (146.5) > Ca (204.6) > N (128.1) > Mg (75.8) > S (50.3) > P (3.7) and K (397.2) > N (191.3) > S (241.2) > Ca (167.8) > Mg (131.0) > P (14.1). The maintenance/production fertilization in cactus pear should be planned according to productive potential, fertilization and harvest managements, and cultivation region, based on nutritional requirement and considering the nutrient recovery efficiency

Dinâmica de perfilhamento em capim-massai adubado com nitrogênio e pastejado por ovinos.

Resumo: Avaliou-se a dinâmica de perfilhamento do capim-massai sob lotação rotativa com ovinos e adubado com nitrogênio (controle - 0; 400; 800 e 1200 kg N?ha-1?ano-1), num delineamento inteiramente casualizado com medidas repetidas no tempo. As taxa de aparecimento, sobrevivência e mortalidade perfilhos responderam crescentemente às doses de nitrogênio, com as duas primeiras taxas revelando ligeira variação entre os períodos de avaliação. Constatou-se resposta quadrática, alcançando valores máximos com o incremento das doses de nitrogênio para a taxa de florescimento de perfilhos, (0,051 perfilhos?100 perfilhos-1?dia-1, respectivamente) nas doses 613,5 kg de N?ha-1?ano-1, respectivamente. Para a taxa de florescimento, verificou-se oscilação entre os períodos de avaliação. A adubação nitrogenada proporciona mudanças positivas na dinâmica de perfilhamento do capim-massai. Tillering dynamics in massai grass fertilized with nitrogen and grazed by sheep. Abstract: The tillering dynamics in massai grass subjected to different nitrogen (N) fertilization levels (control - 0; 400; 800 and 1200 kg N?ha-1?year-1) and under rotational stocking with sheep was evaluated. A completely randomized design with measurements repeated in time was adopted. The tiller appearance, survival and mortality rates were increased with the nitrogen levels, with the two rate revealing slight variation between the periods of evaluation. There was showed quadratic response reaching maximum values with increasing levels of nitrogen for tillers flowering rate (0.051 tillers?100 tillers-1?day-1, respectively) for levels 613.5 kg of N?ha-1?year-1, respectively. For the flowering rate and reproductive basal tillers population density was differences observed between the evaluation periods. The nitrogen fertilization provide positive responses to the tillering dynamics of massai grass

Densidade e estrutura do resíduo pós-pastejo em capim-massai adubado com nitrogênio e pastejado por ovinos.

Resumo: Somando-se ao suprimento nutricional, em especial a adubação nitrogenada, é imperativo o monitoramento rigoroso da condição residual do pasto. Objetivou-se avaliar a densidade e a estrutura do resíduo pós-pastejo em capim-massai adubado com N (0; 400; 800 e 1200 kg de N?ha-1?ano-1) e pastejado por ovinos num delineamento inteiramente casualizado com medidas repetidas no tempo. A elevação das doses de N influenciou as variáveis: densidade total de forragem residual, de forragem verde residual, de colmo verde residual, a relação lâmina foliar/colmo e o índice de qualidade da biomassa residual. Os ciclos de pastejo não exerceram alterações sobre a relação material vivo/material morto residual e densidade de forragem verde residual, sendo as demais variáveis modificadas pelos ciclos. A adubação nitrogenada proporciona respostas positivas sobre a densidade e estrutura do resíduo pós-pastejo do capim-massai. After grazing canopy structure and density of massai grass fertilized with nitrogen and grazed by sheep. Abstract: In addition to the nutrient supply, especially nitrogen, it is imperative to monitor carefully the residual condition of grass. To evaluate after grazing canopy structure and density of massai grass fertilized with nitrogen (0, 400, 800 and 1200 kg N?ha-1?year-1) and grazed by sheep in a completely randomized design with repeated measurements over time, this research was conducted. The nitrogen levels influenced the variables: residual total herbage density, residual green herbage density, residual green stem density, leaf/culm ratio and residual biomass quality index. The grazing cycles did not exert changes on the residual alive/senescent relation and residual green herbage density, being the others variables modified by the cycles. The nitrogen provides positive responses on after grazing canopy structure and density of massai grass

Análise da pulsatilidade da testosterona em mulheres com ciclos menstruais ovulatórios

OBJECTIVE: To evaluate the pattern of the pulsatile secretion of testosterone in normal menstrual cycle. METHODS: Eight healthy women with ovulatory menstrual cycles were enrolled. Blood samples were collected at ten-minute intervals for six hours, starting between 7 and 8 am, after a ten-hour fasting, in three phases: mid-follicular (Day 7), late follicular (Day 12) and mid-luteal phase (Day 21). Samples were assayed for testosterone, LH and the baseline also for SHBG. RESULTS: Testosterone pulse frequency, mean amplitude pulse, percentage of increment in pulse amplitude, mean duration of pulses and pulse interval were similar in the three phases. LH pulsatility was statistically different among the three phases (p < 0.001) representing normal ovulatory cycles. CONCLUSIONS: These data increase the knowledge about the testosterone secretion profile in the human menstrual cycle and can be used as a contribution to clinical investigation in both hyperandrogenism and androgen insufficiency syndrome.OBJETIVO: Avaliar o padrão pulsátil da secreção da testosterona em mulheres normais. MÉTODOS: Oito mulheres saudáveis com ciclos ovulatórios foram selecionadas. Amostras sanguíneas foram coletadas a cada dez minutos durante seis horas, começando entre 7 e 8 h da manhã, após dez horas de jejum, nas três fases do ciclo menstrual: folicular média (Dia 7), folicular tardia (Dia 12) e lútea (Dia 21). Foram mensurados: testosterona, LH e, no basal, também SHBG. RESULTADOS: A frequência dos pulsos de testosterona, média da amplitude do pulso, porcentagem do incremento da amplitude, duração e intervalos dos pulsos foram similares nas três fases (p > 0,05). A pulsatilidade do LH foi estatisticamente diferente entre as três fases (p < 0,001), caracterizando padrão característico do ciclo ovulatório normal. CONCLUSÕES: Esses dados aumentam o conhecimento sobre o padrão de secreção da testosterona no ciclo menstrual humano e representam uma contribuição para a investigação clínica, tanto no hiperandrogenismo como na síndrome de insuficiência androgênica

Forage biomass and water storage of cactus pear under different managements in semi-arid conditions.

Abstract: Forage biomass production and water storage (WS) was evaluated in cactus pear cv. Gigante fertilized with combinations of nitrogen (10, 70, 100, 130, and 190 kg ha-1 yr-1 N) and phosphorus (10, 70, 100, 130, and 190 kg ha -1 yr -1 P2O5) in annual (AH) and biennial (BH) harvest frequencies, in Quixadá and Tejuçuoca, Brazil. A randomized complete block design was used in a split-plot arrangement with four replications. In Quixadá, the maximum total forage biomass (TFB) recorded in the AH was 3,522.9 kg ha -1 yr -1 for the N/P2O5 combination of 134.6/190.0 kg ha -1 yr -1, and in the BH, the maximum TFB of 1,583.2 kg ha -1 yr -1 was recorded for the N/P2O5 combination of 114.6/136.8 kg ha -1 yr -1. In Tejuçuoca, the maximum TFB recorded in the AH was 9,783.0 kg ha -1 yr -1 for the N/P2O5 combination of 137.7/190.0 kg ha -1 yr -1, and in the BH, the maximum TFB of 12,124.0 kg ha -1 yr -1 was recorded for the N/P2O5 combination of 190.0/56.8 kg ha -1 yr -1. In Quixadá, the maximum WS recorded in the AH -was 39.1 kg ha -1 mm -1 for the N/P2O5 combination of 161.0/190.0 kg ha -1 yr -1, and in the BH, the maximum WS of 11.3 kg ha -1 mm -1 was recorded for the N/P2O5 combination of 113.5/158.7 kg ha -1 yr -1. In Tejuçuoca, the maximum WS recorded in the AH was 196.1 kg ha -1 mm -1 for the N/P2O5 combination of 190.0/190.0 kg ha -1 yr -1, and in the BH, the maximum WS of 265.5 kg ha -1 mm -1 was recorded for the N/P2O5 combination of 190.0/10.0 kg ha -1 yr -1. To achieve the persistence and longevity of the cactus pear cv. Gigante, the management with BH and fertilization with the N/P2O5 combination of 114.6/136.8 kg ha -1 yr -1 (in regions similar to Quixadá) and N/P2O5 combination of 190.0/56.8 kg ha -1 yr -1 (in regions similar to Tejuçuoca) is recommended