Management practices might alter soil chemical properties. This study evaluated soil chemical properties in a forage cactus Opuntia stricta (Haw.) Haw. (‘Orelha de Elefante Mexicana’) (OEM) production system in the Brazilian semiarid region. The experiment was established in June 2011, and the design was a split-split-plot in randomized complete blocks, in which the main plots were formed by distinct levels of organic fertilizer (cattle manure) (0, 10, 20, and 30 Mg ha⁻¹ year⁻¹), the subplots were formed by different levels of N inorganic fertilizer applied as urea (0, 120, 240, and 360 kg N ha⁻¹ year⁻¹), and the sub-subplots were distinguished by the distinct OEM harvesting frequency (annual or biennial). Soil samples were collected for chemical analysis, C and N contents analysis, and stocks analysis at 0 to 10 and 10 to 20 cm depths in August 2019. Organic fertilizer contributed to a linear increase in soil pH, Ca²⁺, Na⁺, sum of bases (SB), cation exchange capacity (CEC), and base saturation (V) at both depths (p < 0.05). With the application of 30 Mg ha⁻¹ year⁻¹ of cattle manure, there was storage of approximately 126 Mg C ha⁻¹ and 13 Mg N ha⁻¹ at 0 to 20 cm depths. Managing OEM with organic fertilizer and a biennial frequency of harvesting affects the soil’s chemical characteristics in cactus orchards, and it is a sustainable alternative for semiarid regions.

Elephant grass [Cenchrus purpureus (Schum.) Morrone] is a tropical forage grass widely used in ruminant feeding in tropical and subtropical areas, mainly in cut-and-carry systems due to is high potential for herbage accumulation. However, most common genotypes (tall genotypes) generally show an early stem elongation, which contributes to a rapid decline in the forage nutritive value. Dwarf elephant grass types usually present less stem elongation and may be considered an option for the production of high nutritive value forage in cut-and-carry systems. The aims of this study were to evaluate and explain variations in herbage characteristics and kinetics of in vitro gas production of irrigated elephant grass genotypes (two tall-types – Elephant B and IRI-381 – and two dwarf-types genotypes – Mott and Taiwan A-146 2.37) under two harvest frequencies (60 and 90 days) in the dry and rainy seasons of two years. Herbage characteristics varied among genotypes, harvest frequency and seasons. Dwarf genotypes showed better in vitro fermentation parameters with the advancement of maturity compared to the tall size genotypes. Harvesting tall genotypes at a higher frequency (60-day) contributed to improving the fermentation, while dwarf elephant grass maintained greater fermentation when less frequent harvests were adopted (90-day).

Fifteen accessions of Macroptilium lathyroides (L.) Urb. were collected in three semi-arid Brazilian municipalities and evaluated to characterize their morphology and yield in a greenhouse for three 60-day growth cycles. In the first two cycles, chlorophyll a and b, carotenoids, and soil plant analysis development index (SPAD) were estimated, and root dry mass was determined in the third cycle. Data were analyzed by analysis of variance and Kruskall-Wallis test when appropriate. Principal component analysis and clustering were performed for all accessions. Leaf length, leaf number, leaf mass and total aerial mass production differed between accessions and growth cycles. Root dry mass differed between accessions and SPAD index and stem dry mass between growth cycles. The first two principal components (representing 67% of the variation) generated three clusters based on leaf and leaflet length, plant height, and total aerial mass. The variation in plant height, leaf number, and leaf and total aerial mass in all accessions of M. lathyroides indicates that there is merit in collecting further germplasm of this species to support future breeding programs. Access 62F (Bom Jardim) stands out considering most of the morphological and productive. Quinze acessos de Macroptilium lathyroides (L.) Urb. foram coletados, caracterizando sua morfologia e produtividade em casa de vegetação durante três ciclos de crescimento (60 dias). Nos dois primeiros ciclos foram estimadas clorofila a e b, carotenoides e índice de desenvolvimento de plantas do solo (SPAD) e a massa seca de raízes foi determinada no terceiro ciclo. Utilizou-se análise de variância e teste de Kruskall-Wallis quando adequado. Análise de componentes principais e agrupamento foram realizados para todos os acessos. O comprimento foliar, número de folhas, massa foliar e a produção de massa aérea total foram diferentes entre os acessos e os ciclos de crescimento. A massa seca das raízes apresentou diferença entre os acessos e o índice SPAD e a massa seca do caule entre os ciclos de crescimento. Os dois primeiros componentes principais (representando 67% da variação) geraram três grupos a partir do comprimento da folha e do folíolo, altura da planta e massa aérea total. A variabilidade na altura das plantas, número de folhas e massa aérea total e foliar em todos os acessos de M. lathyroides indica que há mérito em coletar mais germoplasma desta espécie para apoiar futuros programas de melhoramento. O acesso 62F (Bom Jardim) destaca-se pela maioria das características morfológicas e produtivas avaliadas.

Although Stylosanthes species are widely recognized for their nutritional value and adaptation to tropical and semi-arid environments, information on how natural edaphoclimatic variation influences their nutritional and phytochemical composition remains limited. Thus, our objective was to evaluate the chemical composition of naturally occurring Stylosanthes plants across the transitional (Agreste) and semiarid (Sertão) regions of Pernambuco, Brazil, according to collection site and season. Plants were collected at six sites, three in the Sertão and three in the Agreste, during the rainy and dry seasons, using a randomized complete block design with four replications. Crude protein, neutral detergent fiber, and acid detergent fiber varied with collection site and season. Condensed tannin concentrations increased by 38.7% in the Agreste from the rainy to the dry season, whereas no seasonal differences were observed in the Sertão. Total phenol concentrations increased by 19.4% and 30.1% in the Agreste and Sertão, respectively. Principal component analysis showed that the first two components explained 84.22% of the total variation. Rainfall was the environmental variable most strongly associated with condensed tannin and total phenol concentrations (r = -0.54 and -0.86, respectively). We conclude that the chemical composition of Stylosanthes varied by collection site and season, reflecting the edaphoclimatic conditions and the plant's phenological stage at harvest.