Browsing by Author "Cartmill AD"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
- ItemAboveground Structural Attributes and Morpho-Anatomical Response Strategies of Bromus valdivianus Phil. and Lolium perenne L. to Severe Soil Water Restriction(MDPI (Basel, Switzerland), 2023-12-01) Zhang Y; García-Favre J; Hu H; López IF; Ordóñez IP; Cartmill AD; Kemp PD; Głab TGrass species have a range of strategies to tolerate soil water restriction, which are linked to the environmental conditions at their site of origin. Climate change enhances the relevance of the functional role of anatomical attributes and their contribution as water stress tolerance factors. Morpho-anatomical traits and adjustments that contribute to drought resistance in Lolium perenne L. (Lp) and Bromus valdivianus Phil. (Bv), a temperate humid grass species, were analysed. The structure of the leaves and pseudostems (stems only in Lp) grown at 20–25% field capacity (FC) (water restriction) and 80–85% FC (control) were evaluated by making paraffin sections. In both species, water restriction reduced the thickness of the leaves and pseudostems, along with the size of the vasculature. Bv had long and dense leaf hairs, small and numerous stomata, and other significant adaptive traits under water stress, including thicker pseudostems (p ≤ 0.001), a greatly thickened bundle sheath wall (p ≤ 0.001) in the pseudostem to ensure water flow, and a thickened cuticle covering on leaf surfaces (p ≤ 0.01) to avoid water loss. Lp vascular bundles developed throughout the stem, and under water restriction the xylem vessel walls were strengthened and lignified. Lp leaves had individual traits of a ribbed/corrugated-shaped upper surface, and the stomata were positioned to maintain relative humidity outside the leaf surface. Water restriction significantly changed the bulliform cell depth in Lp (p ≤ 0.05) that contributed to water loss reduction via the curling leaf blade. This study demonstrated that the two grass species, through different morphological traits, were able to adjust their individual tissues and cells in aboveground parts to reach similar physiological functions to reduce water loss with increased water restriction. These attributes explain how both species enhance persistence and resilience under soil water restriction.
- ItemEffects of combined nitrogen and phosphorus application on soil phosphorus fractions in alfalfa (Medicago sativa L.) production in China.(Frontiers Media S.A., 2024-05-28) Yang K; Li S; Sun Y; Cartmill AD; López IF; Ma C; Zhang Q; Nazir RNitrogen (N) and phosphorus (P) fertilizers change the morphological structure and effectiveness of P in the soil, which in turn affects crop growth, yield, and quality. However, the effects and mechanism of combined N and P application on the content of P fractions and the transformation of effective forms in alfalfa (Medicago sativa L.) production is unclear. This experiment was conducted with four levels of N: 0 (N0), 60 (N1), 120 (N2) and 180 kg·ha-1 (N3); and two levels of P (P2O5): 0 (P0) and 100 kg·ha-1 (P1). The results indicated that, under the same N level, P application significantly increased soil total N, and total P, available P, and content of various forms of inorganic P when compared to no P application, while decreasing the content of various forms of organic P and pH value. In general, under P0 conditions, soil total N content tended to increase with increasing N application, while total P, available P content, pH, inorganic P content in all forms, and organic P content in all forms showed a decreasing trend. When compared to no N application, insoluble P (Fe-P, O-P, Ca10-P) of the N application treatments was reduced 2.80 - 22.72, 2.96 - 20.42, and 5.54 - 20.11%, respectively. Under P1 conditions, soil total N and O-P tended to increase with increasing N application, while, pH, Ca2-P, Al-P, Fe-P, Ca10-P, and organic P content of each form tended to decrease. Total P, available P, and labile organic P (LOP) of N application reduced 0.34 - 8.58, 4.76 - 19.38, and 6.27 - 14.93%, respectively, when compared to no application. Nitrogen fertilization reduced the soil Ca2-P ratio, while P fertilization reduced soil Fe-P, moderately resistant organic P (MROP), and highly resistant P (HROP) ratios, and combined N and P elevated the Ca8-P to LOP ratio. The results of redundancy analysis showed that soil total N content, available P content, and pH were the key factors affecting the conversion of P fractions in the soil. Nitrogen and P reduced the proportion of soil insoluble P, promoted the activation of soil organic P, resulting in accumulation of slow-acting P in the soil, thereby improving the efficiency of soil P in alfalfa production.
- ItemNutrient Uptake and Partitioning in Oriental Lilium(MDPI (Basel, Switzerland), 2023-04-10) Alvarado-Camarillo D; Cárdenas-Medina G; Valdez-Aguilar LA; Preciado-Rangel P; Cartmill AD; Baldi EFertilization programs in lilium are suggested to start after shoot emergence or when the flower buds become visible because the nutrients stored in the bulb are adequate to meet plant demands at the transplant time. Defining plant nutrient uptake is essential to determine the periods of high demand and the amounts at which they should be provided. The objective of this study was to model the nutrients accumulated in Oriental lilium to provide insight into the design of environmentally sound fertilization programs. The most demanded macronutrient was K (1272.8 mg/plant), followed by N (719.1 mg/plant) and Ca (119.7 mg/plant), while Zn (140.7 mg/plant) and Fe (137.7 mg/plant) were the most demanded micronutrients. At the end of the season, most of the Fe (78.0%), P (55.0%) and N (54.3%) originated from the bulb, whereas most of the Ca (86.5%), Mn (84.8%) and Mg (62.9%) were uptaken by roots. During the first 15 days after transplant, 35.1% of the N in the shoot was absorbed from the substrate, as well as 91.0% Mg, 68.6% S, 49.6% K and 13.0% P, suggesting that fertilization for lilium should start at the transplant time. The results suggest that Ca, Fe, Zn and Cu were remobilized from the bulb.
- ItemPasture Performance: Perspectives on Plant Persistence and Renewal in New Zealand Dairy Systems(MDPI (Basel, Switzerland), 2024-08) Cartmill AD; Donaghy DJ; Hou FPasture systems dominate the landscape of Aotearoa, New Zealand, and are an integral component of sustainable and resilient livestock production. Predicting the response, performance, and dynamics of pasture species and adapting management practices is key to the long-term economic and environmental sustainability and resilience of the agricultural sector. However, there is limited information on the long-term productivity, performance, and persistence of forage cultivars and species for pasture production systems, particularly when linked to grazing and animal performance. Here, we sought to reduce scientific uncertainty, inform modelling efforts, and contribute to a predictive framework for understanding pasture performance, persistence, and renewal. Inter-annual pasture renewal (direct drilling and cultivation) rates vary by region and year, reflecting both opportunity and problem-based drivers, with the highest pasture renewal rates in Waikato and Canterbury on the North and South Island, respectively.
- ItemResponse of Strawberry to the Substitution of Blue Light by Green Light in an Indoor Vertical Farming System(MDPI (Basel, Switzerland), 2022-12-28) Avendaño-Abarca VH; Alvarado-Camarillo D; Valdez-Aguilar LA; Sánchez-Ortíz EA; González-Fuentes JA; Cartmill AD; Jeong BRIndoor production systems with light emitting diode (LED) lamps are a feasible alternative for increasing strawberry productivity by reducing the incidence of pests and diseases and the damage caused by extreme weather events. Blue (BL) and red (RL) LED light are considered the most important light spectra for photosynthesis and crop yield; however, recent studies have demonstrated that the beneficial effects of green light (GL) have been underestimated. This information would be of particular importance for strawberry production in controlled-environments/vertical farming systems as it may lower input costs and enhance production efficiency and quality and marketability. The present study aimed to define the effect of GL in combination with BL in strawberry. A proportion of 20% GL (20% BL + 60% RL) of total photosynthetic photon flux density was beneficial for plant growth and productivity; however, a 27% GL (12% BL + 61% RL) proportion was detrimental or comparable to that with 6% GL (36% BL + 58% RF). Total dry mass increased 51% when plants were illuminated with 20% GL lamps compared to those with 6% GL; the most impacted plant part was the root as it increased by 155%. The higher yield was observed with GL at 20%, but further increasing GL to 27% resulted in reduced yield. GL at 20% and 27% exhibited higher photosynthesis but reduced transpiration, stomatic conductance, and internal CO2, which in turn increased instantaneous and intrinsic water-use efficiency. Plants with the highest yield (20% GL) exhibited lower total soluble solids in fruits but still the values obtained were acceptable (8.25 °Brix); these fruits contained a high total sugars and phenolics concentration but a reduced antioxidant scavenging capacity. High proportions of GL were associated with a higher leaf and fruit Ca and a higher leaf P and K, which may be due to the increased allocation of biomass to the roots. In conclusion, GL at 20% and BL at 20% resulted in the best growth and yield parameters, enhanced net photosynthesis rate, water-use efficiency and fruit quality attributes. The effects of GL observed in this study may also be important for other high-value horticultural crops suitable for indoor vertical farming.
- ItemSubirrigation of container-grown tomato I: Decreased concentration of the nutrient solution sustains growth and yield(MDPI (Basel, Switzerland), 2019-10-02) García-Santiago JC; Valdez-Aguilar LA; Cartmill AD; Cartmill DL; Juárez-López P; Díaz-Pérez JCSubirrigation of containerized vegetable crops is a promising strategy to increase water and fertilizer use efficiency. However, the nutrient solution may cause salts accumulation in the substrate top layer. The objective of this study was to determine the effect of nutrient solution concentration in container-grown tomato under surface drip-irrigation and subirrigation. The plants were irrigated with solutions at concentrations of -0.072, -0.058 and -0.043 MPa (100%, 80% and 60% of Steiner's nutrient solution, respectively). Except at the highest concentration, the greatest yields occurred in subirrigated (10.6 kg plant-1) compared to drip-irrigated plants (9.5 kg plant-1). In drip-irrigated plants, yield was higher with the highest solution concentration. The increased yield in subirrigated plants at low solution concentrations was related with increased fruit N and Ca content. The higher accumulation of N, P, K and Ca demonstrates that subirrigation allows for increased nutrient use efficiency, particularly when using nutrient solutions of low concentration. Water use efficiency was markedly increased in subirrigated tomato, as 300 to 460 g of fruit L-1 were produced, compared to 50 g L-1 in drip-irrigated plants. Our results indicate that subirrigation is a feasible system for soilless-cultivated tomato provided the nutrient solution is reduced to a 60% of the total concentration.
- ItemSubirrigation of container-grown tomato II: Physical and chemical properties of the growing medium(MDPI (Basel, Switzerland), 2019-10-24) García-Santiago JC; Valdez-Aguilar LA; Cartmill DL; Cartmill AD; Juárez-López P; Alvarado-Camarillo DSubirrigation of containerized vegetable crops is a promising strategy to increase water and nutrient use efficiency, however, the longer growing seasons for cultivation of vegetable species may cause marked changes in the physical and chemical substrate properties. This study determined the effects of the irrigation system, subirrigation vs. drip-irrigation, and the concentration of the nutrient solution on the substrate physical and chemical properties in containerized tomato plants. Plants were irrigated with solutions at concentrations of -0.072, -0.058 and -0.043 MPa. Root dry weight of subirrigated plants was decreased by 35% in the substrate top layer when the highest concentration was used. Substrate electrical conductivity increased while pH was acidified as solution concentration increased and from the bottom to the top substrate layers in subirrigated plants. Salts buildup was associated with increased concentration of oxalic and tartaric acids and pH acidification. The improved substrate physical and chemical properties in subirrigated plants were associated with higher fruit yield (11.0 kg per plant) provided nutrient solution concentration was reduced to -0.043 MPa; in contrast, the highest yield in drip-irrigated plants (10.1 kg per plant) was obtained when the solution concentration was -0.072 MPa. In conclusion, subirrigation with reuse of the nutrient solution is a promising strategy to reduce water waste through runoff and leaching as water use efficiency increases due to greater water retention properties in the substrate, the maintenance of an EC within a range the plants can tolerate, and a lower acidification of substrate pH.
