Forage Grasses Research Articles

Yield and quality responses of Megathyrsus maximus and Cynodon spp. forage grasses to irrigation

Periodic variations in rainfall have resulted in longer periods of drought in traditional rainfed livestock systems on savanna areas in Brazil. However, irrigation management techniques and rotational grazing have improved the productivity of these systems by mitigating soil water stress on forage grasses. The objectives of this research were to evaluate the response of Megathyrsus maximus cv. Tanzania and Cynodon spp. cv. Tifton 85 (Cynodon nlemfuensis × Cynodon dactylon) forage grasses to irrigation, and to determine their irrigation water productivity (IWP). The experiment was conducted at the University of São Paulo in Brazil. Plant height (PH), dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were measured, and IWP was calculated. Tifton 85 had a higher CP content than Tanzania but a lower average DM yield. The irrigation management (IM) treatments did not influence CP levels of both forage grasses, but in most situations, did affect their average DM yield. The IWP of Tanzania and Tifton 85 forage grasses did not differ among irrigation management treatments.

Replenishment of the VIR perennial forage crops collection with samples from a collecting mission in Tambov and Ryazan provinces in 2018

The purpose of the collecting mission was to replenish the collection of perennial forage crops with crop wild relatives (CWR) of interest for breeding purposes, as well as for the subsequent preservation of forage CWR diversity in natural populations. The mission was tasked to conduct a survey of the territory along the middle and lower Tsna river and collect seeds of wild perennial and annual forages. Coordinates of collecting sites were recorded and sites mapped together with the collecting mission route. Two districts of the Tambov and two districts of Ryazan provinces were explored. As a result, 93 seed samples were collected. Out of these, 47 samples were perennial forage grasses, 39 perennial and annual forage legumes, and 7 belonged to other families. The main part of legumes was represented by Medicago species (11 samples of Medicago falcata L., M. varia Mart., M. lupulina L.) and clover (11 samples of Trifolium hybridum L., T. incarnatum L., T. medium L., T. pratensis L., T. repens L.); among the grasses there were Bromopsis inermis (Leyss.) Holub, Poa angustifolia L., Dactylis glomerata L., and Phleum pratense L.

Structural carbohydrate and lignin content of perennial cereal forage grasses depending on the growth phase and digital innovations in forage composition analysis

The article is devoted to the study of the content of cell wall carbohydrates – neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL) – in cereal forage grasses depending on the growth phases. An increase in all cell wall fractions was revealed as the growth phases changed. The content of acid detergent fiber, neutral-detergent fiber and acid detergent lignin (% in dry matter) in cereal forage grasses (awnless brome, meadow fescue, meadow timothy) is 31‑32, 50‑55, 4‑6 before earing; in the earing phase – 32‑37, 55‑65, and 5‑6; in the flowering phase – 40‑45, 70‑72, 7‑9, respectively. As grasses grow, their composition changes with the accumulation of cell walls. The increase in the proportion of neutral detergent fiber occurs mainly due to an increase in the proportion of cellulose and a decrease in the proportion of hemicellulose, which is consistent with a higher digestibility of grasses in the early growth stages. According to the results of the study, the relationship between crude fiber and acid detergent fiber was closer (n = 64, s = 2.4%, r = 0.93) than between crude fiber and neutral detergent fiber (n = 64, s = 4.4%, r = 0.87). As the composition of grass changes daily during the growing season, it is advisable to determine its composition as soon as possible. As chemical methods are time-consuming, an express method based on an infrared analyzer can be used to solve this problem. The express method involves, after the grinding of the sample, sequential operations such as calibrating the analyzer, placing the sample in the analyzer and analyzing the samples with the analyzer. This means that this method is also quite time-consuming. To obtain information more quickly (two hours), digital technologies are now increasingly being used. The method based on digital technologies involves the sequential execution of the following operations: UAV launch, crop survey, transmission of multispectral data to the server, information processing and calculation of crude fiber content.

Influence of induced drought on photosynthetic performance in Dactylis glomerata varieties during the early growth stage

Drought significantly impacts the growth and yield of forage grasses, particularly its effect on Dactylis glomerata photosynthetic apparatus during the initial phase of development remains largely unknown. This study investigated the effects of drought on physiological parameters of various D. glomerata varieties. The seedlings obtained after seed germination under optimal and simulated drought conditions by PEG 6000 (three variants) were planted in small pots filled with garden substrate. Over a span of 42 days, the plants were initially kept well-watered (70% capillary water capacity, CWC), after which half of the seedlings from each variant were subjected to drought. This drought stress was applied during the tillering phase for 12 days. Subsequently, the plants were rehydrated (at 70% CWC) and allowed to recover for 14 days. Throughout both drought and recovery periods, measurements were taken. Leaf chlorophyll fluorescence parameters were assessed, and the JIP-test analysis was utilised to provide detailed insights into the functionality of D. glomerata photosynthetic apparatus under drought stress and post-recovery conditions. Several parameters were identified as indicative of the plants’ sensitivity to drought, such as performance indices PI ABS and PI tot, along with quantum yield parameters Ψ E0, φ E0, and φ P0. The results highlighted that var. Minora and Tukan exhibited greater tolerance to water deficit when compared to the other varieties studied. They showed a large increases in PIABS and PItot values after drought stress as well as after the re-watering (recovery period) compared to control plants. This suggests their potential for better adaptation to drought conditions.

Adapting the grassland model BASGRA to simulate yield and nutritive value of whole-crop barley

Ensiling of whole-crop biomass of barley before full maturity is common practice in regions with a short growing season. The developmental stage of barley at harvest can have a large impact on yield and nutritive composition. The relationships between crop growth, environmental conditions and crop management can be described in process-based simulation models. Some models, including the Basic Grassland (BASGRA) model, have been developed to simulate the yield and nutritive value of forage grasses, and usually evaluated against metrics of relevance for whole-crop silage. The objectives of this study were to: i) modify the BASGRA model to simulate whole-crop spring barley; ii) evaluate the performance of this model against empirical data on dry matter (DM) yield and nutritive value attributes from field experiments, divided into geographical regions; and iii) evaluate DM yield, nutritive value and cutting date under current and future climate conditions for three locations in Sweden and four cutting regimes. Main model modifications included addition of a spike pool, equations for carbon (C) and nitrogen (N) allocation to the spike pool and equations for C and N translocation from vegetative plant parts to spikes. Model calibration and validation against field trial data from Sweden, including samples harvested from late anthesis stage to hard dough stage that were either pooled or divided into regions, showed better prediction accuracy, evaluated as normalised root mean squared error (RMSE), of neutral detergent fibre (NDF) (7.58–18.4%) than of DM yield (16.8–27.8%), crude protein (15.5–23.2%) or digestible organic matter in the DM (DOMD) (12.0–22.2%). Model prediction using weather data representing 1990–2020 and 2021–2040 climate conditions for three locations in Sweden (Skara, Umeå, Uppsala) showed lower DM yield, earlier harvest and slightly higher NDF concentration on average (across locations and developmental stage at cutting) when using near-future climate data rather than historical data. The model can be used to evaluate whole-crop barley performance under production conditions in Sweden or in other countries with similar climate, soils and crop management regimes.

Effects of leaf and stem maturation on nutritional value in Megathyrsus maximus.

Megathyrsus maximus is a forage grass native to Africa but widely cultivated in tropical and subtropical regions of the world where it is part of the grazing food chain. This study aimed to evaluate five M. maximus genotypes for the effect of maturity on their morpho-agronomic traits, nutritional composition and digestibility, and to correlate their leaf blade and stem anatomy with their nutritional value. The proportion of sclerenchyma tissues increased as maturity was reached, while lignin accumulation was differentiated between genotypes. Gatton Panic, Green Panic and Mutale genotypes maintained their acid detergent lignin (ADL) values for leaf blades in the three cuts evaluated. In sacco ruminal dry matter disappearance was lower in Green Panic genotype at the vegetative stage for stems, but not for leaf blades. Significant positive correlations were found between dry matter disappearance and mesophyll tissues, and the latter were negatively correlated with neutral detergent fiber (NDF) and ADL. Our results strongly indicate that cutting age and genotype affected the nutritional value of M. maximus leaf blades and stems, with a more pronounced loss of quality in stems than in leaf blades. We recommend increasing the frequency of grazing at early stage or anticipating the stage of stem elongation in Green Panic to produce forage with better nutritional value. © 2023 Society of Chemical Industry.

Selection of forage grasses for cultivation under water-limited conditions using Manhattan distance and TOPSIS.

Extreme weather events, such as severe droughts, pose a threat to the sustainability of beef cattle by limiting the growth and development of forage plants and reducing the available pasture for animals. Thus, the search for forage species that are more tolerant and adapted to soil water deficit conditions is an important strategy to improve food supply. In this study, we propose utilizing the mathematical concept of the Manhattan distance to assess the variations in the morphological variables of tropical forage grasses under water-limited conditions. This study aimed to select genotypes of tropical forage grasses under different water stress levels (moderate or severe) at this distance and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Nine varieties from five species were examined. Forage grasses were grown in 12-L pots under three soil irrigation regimes [100% pot capacity-PC (well-irrigated control), 60% PC (moderate drought stress), and 25% PC (severe drought stress)] with four replicates. Drought stress treatments were applied for 25 days during the forage grass tillering and stalk elongation phases. After exposure to drought stress, the growth and morphological traits of forage plants were evaluated. The results show that the use of the Manhattan distance combined with TOPSIS helps in the genotypic selection of more stable tropical forage grass varieties when comparing plants exposed to moderate and severe drought conditions in relation to the nonstressful environment (control). The 'ADR 300', 'Pojuca', 'Marandu', and 'Xaraés' varieties show greater stability when grown in a greenhouse and subjected to water stress environments. The selected forage varieties can be used as parents in plant breeding programs, allowing us to obtain new drought-resistant genotypes.

Sistema de consórcio de milho com gramíneas forrageiras e o uso de doses reduzidas do herbicida mesotrione

ABSTRACT Sowing forage grass species of the genera Urochloa and Panicum simultaneously with corn can hinder crop grain yield, requiring the application of low herbicide rates for suppressing their growth and preventing potential competition with corn plants. Therefore, the objective of this study was to evaluate the use of low rates of the herbicide mesotrione for inhibiting the growth of forage grass species (Urochloa ruziziensis and Panicum maximum, cultivars BRS Tamani and BRS Zuri) sown simultaneously with corn crop, as well as the recovery capacity of these grasses. Two experiments were installed, as first and second crop seasons, in a randomized experimental block design with four replications, using a 3×4 factorial arrangement and three control treatments with corn alone. Each of the three forage grasses was sown simultaneously with corn and subjected to post-emergence application of four mesotrione rates (0, 48, 96, and 144 g ha-1) with atrazine (1.25 kg ha-1). Weeds, forage grasses, and corn plants were evaluated. BRS Tamani was the most tolerant forage to mesotrione, while BRS Zuri was the most sensitive. The application of mesotrione + atrazine in the corn-forage grass intercropping system contributed to weed control. The tested forage grasses did not affect corn grain yield in the first or second crop season, even with no herbicide application.

Trichoderma viride improves phosphorus uptake and the growth of Chloris virgata under phosphorus-deficient conditions.

Phosphorus (P) readily forms insoluble complexes in soil, thereby inhibiting the absorption and utilization of this essential nutrient by plants. Phosphorus deficiency can significantly impede the growth of forage grass. While Trichoderma viride (T. viride) has been recognized for promoting the assimilation of otherwise unobtainable nutrients, its impact on P uptake remains understudied. Consequently, it is imperative to gain a more comprehensive insight into the role of T. viride in facilitating the uptake and utilization of insoluble P in forage grass. This research explored the influence of T. viride inoculation on P absorption and the growth of Chloris virgata (C. virgata) across various P sources. We treated plants with control P (P), tricalcium phosphate (TCP), calcium phytate (PHY), and low P (LP), with and without T. viride inoculation (P+T, TCP+T, PHY+T, LP+T). We analyzed photosynthesis parameters, growth indices, pigment accumulation, P content, leaf acid phosphatase activity. Results demonstrated that T. viride inoculation alleviated inhibition of photosynthesis, reduced leaf acid phosphatase activity, and enhanced growth of C. virgata in the presence of insoluble P sources. Additionally, T. viride inoculation enabled the plants to extract more available P from insoluble P sources, as evidenced by a substantial increase in P content: shoot P content surged by 58.23 to 59.08%, and root P content rose by 55.13 to 55.2%. Biomass P-use efficiency (PUE) declined by 38% upon inoculation with T. viride compared to the non-inoculated insoluble P sources, paralleled by a reduction in photosynthetic P-use efficiency (PPUE) by 26 to 29%. Inoculation under insoluble P sources further triggered a lower allocation to root biomass (25 to 26%) and a higher investment in shoot biomass (74 to 75%). However, its application under low P condition curtailed the growth of C. virgata. Our results suggest that T. viride inoculation represents an innovative approach for plants to acquire available P from insoluble P sources, thereby promoting growth amid environmental P limitations. This insight is crucial for comprehending the synergy among forage grass, P, and T. viride.

Nonessential amino acids in tropical ruminant feed: Investigating grass and legume forages of Indonesia.

This study aimed to examine the concentration of nonessential amino acids (NEAAs) in ruminant feed in tropical areas, with a focus on forage grasses and legumes in Indonesia. A total of 11 grasses (Chrysopogon zizanioides, Brachiaria brizantha, Brachiaria humidicola, Paspalum dilatatum, Paspalum atatum, Chloris gayana, Pennisetum polystachion, Panicum maximum, Cenchrus biflorus, Andropogon canaliculatus, and Digotaria decumbens) and six legumes (Arachis hypogaea, Pueararia Javanica, Centrosema pubescens, Clitoria ternatea, and Arachis pintoi) were analyzed for NEAA content using high-performance liquid chromatography (HPLC). Based on the results of this research, it was found that almost all NEAA content in forage was less than 3% (Serine (Ser), Alanine (Ala), Glycine (Gly), Tyrosine (Tyr), Proline (Pro), Cysteine (Cys), and Asparagine (Asn), except for glutamic (Glu) acid and arginine (Arg) in some legumes. The Glu content in grass ranges from 0.76% to 2.61%, and the Arg content ranges from 0.92% to 2.09%. These two NEAAs were most abundant in grasses and legumes, with concentrations of 5.10% to 6.27% and 3.10% to 5.53%, respectively. Our study concluded that Glu and Arg were the most abundant NEAAs in tropical forages in Indonesia, with legumes having a higher concentration of NEAAs compared to grasses. Among the legumes, A. hypogaea had the highest NEAA content (23.40%), while among the forages, C. zizanioides had the highest NEAA content (12.37%). However, it was observed that neither legumes nor grasses could fulfill the metabolizable TNEAAs requirements for gaining cattle (250 kg of empty body weight gain), unlike commercial concentrates, which were found to meet the requirements, especially for Arg, Glu, and thyronine. The provision of concentrate is necessary to supplement forage to meet the NEAA needs for cattle.

Forage Grass in Static Gas Exchange Chambers Deployed In Southern Amazon Influences Field Measurement of Soil N2O Emissions

Static chambers are used to estimate the exchange of greenhouse gases between the soil and the atmosphere, but the presence of plants inside such chambers can alter gas fluxes. This study aimed to determine the influence of forage grass on N2O fluxes emanating from an oxisol in the southern Amazon region of Brazil. A randomized experiment comprising two treatments, namely static gas exchange Chambers with Grass (CWG) and Chambers with No Grass (CNG) with six replicates of each was performed to determine N2O fluxes over a period of one year. Soil N2O fluxes in the CWG were higher (19.08 µg N2O-N m-2 h-1) than those in the CNG (9.05 µg N2O-N m-2 h-1), most especially during the wet season. Cumulative N2O emissions were 1.60 and 0.72 kg N2O-N ha-1 for the CWG and CNG, respectively. The higher N2O estimates in the CWG may be attributed to the plant transpiration stream and/or to changes in soil attributes induced by the plants. Measurement of N2O emissions from a grass-covered oxisol inside gas exchange chambers may overestimate soil N2O flux in the tropical humid climate of the Southern Amazon.

Leaf senescence in forage and turf grass: progress and prospects

Leaf senescence in forage and turf grass: progress and prospects

First Report of Nigrospora hainanensis Causing Leaf Blight on Brachiaria Griseb in China.

Brachiaria Griseb is an important gramineous forage grown in tropical regions, and also a main grass species uses to restore grasslands in tropical and subtropical regions of China. In August 2022, symptoms of leaf blight were observed on nearly 30% of the Brachiaria forage grass in the base of the Chinese Academy of Tropical Agricultural Sciences, Hainan, China. Symptomatic leaves initially exhibited small, reddish-brown, round or oval spots on their tips, subsequently expanding in size along the leaf margin, and gradually becoming wilted and dry. Twenty leaves showing typical symptoms were randomly collected and pieces (5×5 mm) from the junction of diseased and healthy region were cut, sterilized with 75% alcohol for 30 s, followed by 5% sodium hypochlorite for 30 s. Rinsed three times with sterile water and dried with sterile filter paper. Leaf pieces were placed on potato dextrose agar (PDA) and incubated at 28℃. The colonies were white on the surface and gray on the reverse side. The conidiogenous cells were monoblastic, hyaline, globose or ampulliform, and 6 to 8.7(13.1) ×5 to 7.2 (9) m (n=200). Conidia is single celled, smooth, black, spherical, or ellipsoidal, and (11)13 to 16.5 × (8.2) 10.3 to16.1 m (n=100). Setae were not observed. The morphological characteristics of the isolates were consistent with Nigrospora species. A representative isolate (LNH-5) was selected for genomic DNA extraction. Sequences of the transcribed spacer region of rDNA (ITS), partial translation elongation factor (TEF1), and beta-tubulin fragment (TUB) were amplified using primer pairs ITS1/ITS4(White et al. 1990), EF-728F and EF-986R (Carbone et al. 1999) and Bt2a and Bt2b (Glass et al. 1995), respectively. The sequences of ITS (OQ473493), TEF1 (OQ506059) and TUB gene (OQ506055) were submitted to GenBank. They were 99 to 100% identical to the Nigrospora hainanensis ITS(OM283581.1)(538 out of 519 bp),TEF1(YK019415.1)(274 out of 276 bp),and TUB (OK086377.1)(405 out of 405 bp) sequences. The phylogenetic maximum likelihood analysis using the combined ITS, TEF1 and TUB sequences indicated that the isolate was part of the N. hainanensis clade (100% bootstrap value) that also contained the type isolate LC6979 of this species. Pathogenicity was tested on 15 healthy Brachiaria plants. Fungal conidia were harvested by flooding two-week-old single conidial cultures with sterile water, centrifuging, and adjusting the concentration to 107 spores/mL. Then 10 μL of conidial suspension was dropped onto the surfaces of leaves wounded with a sterile needle. Sterile distilled water was used for control treatment. The test was repeated three times. After inoculation, the plants were kept at 90~100% relative humidity at 25 to 28°C in a greenhouse for two weeks, and monitored daily for lesion development. Seven days post inoculation, all the inoculated leaves presented symptoms similar to those observed under natural conditions, while the control leaves showed no symptoms. The fungus was re-isolated from the diseased tissues by the single spore isolation method (Choi et al. 1999) to complete Koch's postulates. This pathogen has been reported on sugarcane in China (Raza et al., 2019; Zheng et al., 2022). To our knowledge, this is the first report of N. hainanensis causing leaf blight on Brachiaria plants in China.

Assessment for forage grass quality submitted to compaction degrees and nitrogen doses

Assessment for forage grass quality submitted to compaction degrees and nitrogen doses

Productivity and Vegetation Structure Evolution of Complex Mixtures of Perennial Forage Grasses and Leguminous Species, in the Conditions of the Center of Moldova, Romania

Research in our country on the number of species needed to set up temporary grasslands has highlighted the productive and structural superiority of complex mixtures of more than two species. Although for the composition of mixtures is intended to use species and varieties as well as possible adapted to the environment, annual climatic variations sometimes influence the behaviour of the species and therefore productivity. The need to reduce doses of chemical fertilizers in the exploitation of temporary grasslands requires finding solutions to saturate the multiple ecological niches of temporary grassland ecosystems. These can be achieved by using a mix of a larger number of species adapted to the pedo-climatic conditions specific to the cultivation area, as well as by using an appropriate ratio between these species. The purpose of the study was to follow the productivity and evolution of the vegetation structure in some crop mixtures, in different conditions of fertilization. The research was conducted under the conditions of the Center of Moldova from Romania at ARDS Secuieni - Neamţ, during the 2018-2021 period,. The production of dry matter according to the type of mixture and the doses of fertilizers used the percentage of participation of perennial grasses and leguminous species in the vegetation structure, as well as its quality was analysed. From the analysis of the obtained data, the highest feed production (24.82 Mg·ha-1 DM) was obtained in the variant fertilized with N80P40 and sown with the mixture consisting of 70% grasses (Festuca arundinacea 30% + Dactylis glomerata 20% + Festuca pratensis 20%) and 30% leguminous (Medicago sativa 20% + Trifolium pratense 10%). At the first cut, in the mixture of 70% grasses (Festuca arundinacea 30% + Dactylis glomerata 20% + Festuca pratensis 20%) and 30% leguminous (Medicago sativa 20% + Trifolium pratense 10%), the participation percentage of grasses in the vegetation structure varied from 57% in the non-fertilized variant, to 61% in the variant fertilized with N80+40P40. The quality of the feed obtained was good for all variants studied.

GC-MS Analysis of bio-Active compound α-Terpinyl acetate extract of bay leaf having antimicrobial and antifungal properties

This study aimed to assess the phytotoxic and antibacterial properties of á-terpinyl acetate by evaluating the presence of T. pulegioides á-terpinyl acetate chemotype as a source of natural origin, which was examined in 131 sites by hydrodistillation, essential oils were separated, and GC-FID and GC-MS analyses were performed. The phytotoxic impact of this chemotype’s essential oil on monocotyledons and dicotyledons through water and air was investigated in a lab setting; The effect of the essential oil against pathogenic bacteria that affects humans was screened using the broth microdilution method. The findings indicated that á-terpinyl acetate was a very uncommon component in T. pulegioides essential oil, only being discovered in 35% of the habitats that were studied. On the plants under investigation, á-terpinyl acetate (both in essential oil and pure form) exhibited distinct behaviors.á-terpinyl acetate’s phytotoxic impact was more pronounced on the monocotyledons under investigation compared to the dicotyledons. For high economic productivity forage grass monocotyledon Poa pratensis, á-terpinyl acetate essential oil hindered seed germination and radicle development; while, for high economic productivity forage legume dicotyledon Trifolium pretense, it increased seed germination. The essential oil á-terpinyl acetate had a strong antibacterial action against dermatophytes and fungi, but a weaker impact against bacteria and Candida yeasts. Consequently, the á-terpinyl acetate chemotype of T. pulegioides may represent a promising chemical for the development of therapeutics or preventative measures against mycosis.

Breeding for reduced seed dormancy to domesticate new grass species.

Introducing new grass species into cultivation has long been proposed as beneficial to increase the sustainability and diversity of productive systems. However, wild species with potential tend to show high seed dormancy, causing slow, poor, and unsynchronized seedling emergence. Meanwhile, domesticated species, such as cereals, show lower seed dormancy, facilitating their successful establishment. In this work, we conduct a review of phenotypic variation on seed dormancy and its genetic and molecular basis. This quantitative and highly heritable trait shows phenotype plasticity which is modulated by environmental factors. The level of dormancy depends on the expression of genes associated with the metabolism and sensitivity to the hormones abscisic acid (ABA) and gibberellins (GA), along with other dormancy-specific genes. The genetic regulation of these traits is highly conserved across species. The low seed dormancy observed in cereals and some temperate forages was mostly unconsciously selected during various domestication processes. Emphasis is placed on selecting materials with low seed dormancy for warm-season forage grasses to improve their establishment and adoption. Finally, we review advances in the domestication of dallisgrass, where seed dormancy was considered a focus trait throughout the process.

Correction to: The twolined spittlebug (Hemiptera: Cercopidae) invades Hawaiʻi: establishment, biology, and management of a destructive forage grass pest

Correction to: The twolined spittlebug (Hemiptera: Cercopidae) invades Hawaiʻi: establishment, biology, and management of a destructive forage grass pest

Physical characteristics of soybean cultivated under the conditions of integrated agrosystems

Integrated crop-livestock-forest (ICLF) systems involve intercropping of various crops to achieve beneficial and synergistic outcomes, enhancing both economic viability and environmental sustainability. Considering the complexity of integrated agrosystems and the economic importance of soybean production in Brazil, we aimed to investigate the effects of two ICLF systems on the physical characteristics and quality of soybeans produced. The treatments comprised plots (two ha) with either single-row (ICLFS) or triple-row (ICLFT), tree configurations intercropped with soybean (maize and forage grass), and control plots (one ha), whose crops were cultivated under full sunlight (CFS). Soybeans were harvested from plants located at 3, 6, 10 and 15 m from tree bands in the north and south faces of the ICLF systems and at random positions in the CFS plots. The moisture content, electrical conductivity of the exudate solution, hue angle and chroma index of grains harvested from ICLFS and ICLFT were similar to those of CFS-grown soybeans. However, the mass of 1000 grains and the bulk density values of ICLF-grown soybeans were significantly higher (P ≤ 0.05) than those of grains harvested from CFS plots. We conclude that the quality of soybean seeds was not negatively affected by the conditions prevailing in the ICLF systems. Moreover, it appears that the forest component contributed positively to the ecosystem by providing a favorable microclimate for the development of soybean grains.

Calibration and validation of the AquaCrop model for production arrangements of forage cactus and grass in a semi-arid environment

Understanding the best strategies for growing forage plants is important in balancing livestock production, as is the improvement of management techniques aimed at increasing food production. Models that simulate plant growth are therefore important tools for agricultural planning. The aim of this study was to calibrate and validate the AquaCrop model for agricultural systems of the forage cactus, millet and sorghum under different production arrangements. Twelve production units were cultivated from 2019 to 2020, using different cactus clones, and millet and sorghum cultivars, with variations in crop configuration, ground cover, water regime and crop density. Data on the crops (phenology, biometry and biomass throughout the cycle, and productivity at harvest), climate, irrigation, soil and management were observed. In all, data from six production units were used for calibration and six for validation. The performance of the model was evaluated using statistical indices. AquaCrop resulted in admissible errors in predicting the productivity of the crops under evaluation, showing good accuracy with a coefficient of determination greater than 0.80 and performance classified as ‘very good’ (confidence coefficient > 0.80). The Orelha de Elefante Mexicana clone showed the highest mean water productivity (39 g m−2). It was concluded that the model can be used to simulate crop productivity under different cropping arrangements in agricultural environments in the semi-arid region of Brazil with the aim of meeting the forage deficit of livestock in the region.