Modelling nutrient utilization by livestock grazing semiarid rangeland.

Author(s):  
F. D. Richardson ◽  
B. D. Hahn ◽  
S. J. Schoeman
Author(s):  
G.G. Cossens ◽  
M.F. Hawke

During the first 20 years of a Pinus radiata tree rotation, tree growth and pasture yield were assessed under a range of tree spacings at Invermay and Akatore, two coastal sites in Eastern Otago. Pasture yield in association with trees thinned to 100 stems per hectare (sph) was comparable to that from open pasture up to a tree age of 12 years. By the 19th year, however, pasture production declined to 63% of open pasture yield at Invermay and to 42% at Akatore. At 200 and 400 sph at Akatore, pasture yield was similar to that from open pasture at tree age 12 years but declined to 27% and 0% of open pasture yield respectively by year 20. At both Invermay and Akatore, the ryegrass and clover content of open pasture was relatively constant throughout the term of the trial. However, both the ryegrass and clover content of pasture beneath trees began to decline by tree age 12 years with a very rapid decline at Akatore in the number of pasture species at 200 sph by the 19th year. No pasture remained at 400 sph, after 19 years. Livestock carrying capacity with sheep on tree treatments at Invermay decreased from 100% of open pasture at year 6 to 60% by year 10. At Akatore, livestock carrying capacity averaged over the 20-year life of the trial was 4.1 stock units per hectare with a maximum of 8.1 stock units at a tree age of 8 years. Tree growth at both sites was similar, averaging between 1 and 1.1 m/year in height over 20 years, with trees at Invermay at 100 sph averaging 9% greater height and diameter growth than at Akatore. Increasing tree stocking from 100 to 200 to 400 sph at Akatore, resulted in increased tree height, but decreased diameter at breast height. A comparison of the East Otago trees with those in a similar trial at Tikitere (Rotorua) 900 km further north indicated that the southern trees were about 6 years later in their growth pattern by tree age 20 years. On both sites, soil pH tended to be lower in the presence of trees and was significantly lower than in open pasture by year 20. The results and comparisons with the Tikitere data suggest that, in an integrated agroforestry regime, there will be livestock grazing under the trees further into the tree rotation in Otago than in North Island sites. However, slower tree growth would result in a longer rotation time to harvest. Current recommendations to farmers are to plant trees on the less productive areas of the farm and adopt a tree stocking rate which fully utilises the site. Keywords: agroforestry, livestock, pasture, Pinus radiata, soil pH, tree stocking


1958 ◽  
Vol 17 (3) ◽  
pp. 684-692 ◽  
Author(s):  
L. E. Lloyd ◽  
D. G. Dale ◽  
E. W. Crampton
Keyword(s):  

2019 ◽  
Author(s):  
João Macedo Moreira ◽  
Aldrin Martin Pérez-Marin ◽  
Jucilene Silva Araújo ◽  
George Rodrigues Lambais ◽  
Aldo Sales

The study aimed to evaluate the efficiency of nutrient use in three cactus forage (CF) cultivars (Opuntia stricta and Nopalea cochenillifera), 365 days after planting under different types of fertilizer in two research sites (Condado and Riachão) of the semi-arid region of Paraiba state, Brazil. The experimental design was a randomized block design with treatments in a factorial scheme (3×4), three cultivars of CF (Orelha de elefante Mexicana; Miúda; Bahiana), and four fertilizer treatment (Control; Manure; Manure with Nitrogen; Mineral fertilization) with four replications. The CF cultivars did not differ significantly in nutrient use. That means of physiological efficiency by CF cultivars were 1.62, and 2.36 kg of biomass per kg of nutrient applied in Condado and Riachão, respectively. The efficiency of nutrient recovery was 16% for the Condado, according the following order: K> P> Ca> N> C = Mg and 12% for Riachão: K> P> N> C = Ca = Mg. In the two research sites, the treatment with mineral fertilization significantly increased the efficiency use of N, P and K in comparison to the other treatments. The average for efficiency of nutrient utilization was 25% and 19% for Condado and Riachão, respectively, in the following order for Condado: K> P> N> Ca = Mg> C, and Riachão: K> P> N> C> Mg = Ca. In a CF production system aiming to obtain a yearly harvest cycle, it is necessary to replenish of K and P to maintain the nutritional balance between the soil and CF plant.


Soil Horizons ◽  
1984 ◽  
Vol 25 (1) ◽  
pp. 10
Author(s):  
George W. Anderson
Keyword(s):  

2000 ◽  
Vol 14 (6) ◽  
pp. 1862-1869 ◽  
Author(s):  
Christopher B. Goguen ◽  
Nancy E. Mathews

2020 ◽  
Vol 29 (7) ◽  
pp. 2311-2328 ◽  
Author(s):  
César M. A. Correa ◽  
Lívia D. Audino ◽  
Robert Holdbrook ◽  
Rodrigo F. Braga ◽  
Rosa Menéndez ◽  
...  

2021 ◽  
Vol 22 (14) ◽  
pp. 7654
Author(s):  
Chelsie B. Steinhauser ◽  
Colleen A. Lambo ◽  
Katharine Askelson ◽  
Gregory W. Burns ◽  
Susanta K. Behura ◽  
...  

Placental development is modified in response to maternal nutrient restriction (NR), resulting in a spectrum of fetal growth rates. Pregnant sheep carrying singleton fetuses and fed either 100% (n = 8) or 50% (NR; n = 28) of their National Research Council (NRC) recommended intake from days 35–135 of pregnancy were used to elucidate placentome transcriptome alterations at both day 70 and day 135. NR fetuses were further designated into upper (NR NonSGA; n = 7) and lower quartiles (NR SGA; n = 7) based on day 135 fetal weight. At day 70 of pregnancy, there were 22 genes dysregulated between NR SGA and 100% NRC placentomes, 27 genes between NR NonSGA and 100% NRC placentomes, and 22 genes between NR SGA and NR NonSGA placentomes. These genes mediated molecular functions such as MHC class II protein binding, signaling receptor binding, and cytokine activity. Gene set enrichment analysis (GSEA) revealed significant overrepresentation of genes for natural-killer-cell-mediated cytotoxicity in NR SGA compared to 100% NRC placentomes, and alterations in nutrient utilization pathways between NR SGA and NR NonSGA placentomes at day 70. Results identify novel factors associated with impaired function in SGA placentomes and potential for placentomes from NR NonSGA pregnancies to adapt to nutritional hardship.


Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
László Somay ◽  
Viktor Szigeti ◽  
Gergely Boros ◽  
Réka Ádám ◽  
András Báldi

Wood pastures are home to a variety of species, including the dung beetle. Dung beetles are an important functional group in decomposition. Specifically, in terms of livestock manure, they not only contribute to nutrient cycling but are key players in supporting human and animal health. Dung beetles, however, are declining in population, and urgent recommendations are needed to reverse this trend. Recommendations need to be based on solid evidence and specific habitats. Herein, we aimed to investigate the role of an intermediate habitat type between forests and pastures. Wood pastures are key areas for dung beetle conservation. For this reason, we compared dung beetle assemblages among forests, wood pastures, and grasslands. We complemented this with studies on the effects of dung type and season at three Hungarian locations. Pitfall traps baited with cattle, sheep, or horse dung were used in forests, wood pastures, and pasture habitats in spring, summer, and autumn. Dung beetle assemblages of wood pastures showed transient characteristics between forests and pastures regarding their abundance, species richness, Shannon diversity, assemblage composition, and indicator species. We identified a strong effect of season and a weak of dung type. Assemblage composition proved to be the most sensitive measure of differences among habitats. The conservation of dung beetles, and the decomposition services they provide, need continuous livestock grazing to provide fresh dung, as well as the maintenance of wood pastures where dung beetle assemblages typical of forests and pastures can both survive.


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