Report from the conference, ‘identifying obstacles to applying big data in agriculture’

Precision Agriculture - Data-centric technology has not undergone widespread adoption in production agriculture but could address global needs for food security and farm profitability. Participants...     

Recovery and dynamics of decomposing plant residue in soil: an evaluation of three fractionation methods

Our goals in this study were to track the incorporation of plant residue into soil organic matter (SOM) and test the effectiveness of different fractionation methods to evaluate this transformation. We incubated soil amended with ¹³C‐labelled barley (Hordeum vulgare L.) residue and used three fractionation methods based on size (> 250, 53–250, 5–53 and < 5 µm) and density (< 1.7 g cm^?3, i.e. light fraction (LF)) and determined its quantity and the rate of C loss or gain or both in these fractions as decomposition progressed. One method was based on size only, another involved density separation followed by size fractionation and a third separated organic matter fractions by size first and then by density. There were significant quantitative differences between the methods for the amount of residue in the fractions, but there was no effect of fractionation method on the rate of change in the residue that comprised the fractions. The density method did not appear to identify all of the most recently added (i.e. least decomposed) residue in the LF or that there was a redistribution of SOM among the fractions. The amount of residue C and the C:N ratio of the residue in the two smallest fractions increased early during the incubation (0–2 months), but subsequently decreased towards the end. The initially small C:N ratio in the clay fraction probably reflects the accumulation of microbial by‐products from the rapid decomposition of water‐soluble compounds. The subsequent increase and decrease in both residue C and C:N ratio reflects the balance of the accumulation of sorbed water‐soluble compounds and dense plant residue fragments and their mineralization over time. We conclude that clay is a sink for residue C (i.e. microbial metabolites) early during decomposition, and that there is a transfer among fractions and mineralization of residue C as decomposition proceeds. These findings indicate that the clay fraction contains a dynamic pool of C that can cycle within short time‐scales.     

Estrus Synchronization in Sheep and Goats Using Combinations of GnRH,Progestagen and Prostaglandin F2α

The objective of this experiment was to evaluate the effect of GnRH, progestagen and prostaglandin F_2α on estrus synchronization in sheep and goats. Sixty Awassi ewes and 53 Damascus does were used in the study. The experiment started at the beginning of the breeding season (June/July). The same treatments were applied to sheep and goats as follows: no treatment (CON), 14‐day progestagen sponges and 600 IU equine chorionic gonadotropin (S), gonadotropin releasing hormone followed 5 days later by prostaglandin F_2α (GP) and gonadotropin releasing hormone, progestagen sponges for 5 days and prostaglandin F_2α on the day of sponge removal (GSP). None of the ewes in the S group lambed from mating during the induced cycle. A greater lambing rate (p < 0.05) was observed in the GSP group compared with the CON and S groups while the GP group was intermediate. The number of lambs born per lambed ewe was similar among the CON, GP and GSP groups. However, the number of lambs per exposed ewe was greater (p < 0.05) in the GSP than the remaining groups. The induced cycle kidding rate was 77% for all treatments combined. Similar kidding rate were observed among treatments. The numbers of kids born per kidded and exposed doe from mating during the induced estrus were also similar among treatments. Greater numbers of multiple births were observed in the GP and GSP than in the S group. In conclusion, a combination of GnRH, progestagen sponges and PGF_2α can be effective in synchronizing estrus and improving fecundity in sheep and goats. Although the use of GnRH–PGF_2α was effective, the addition of progestagen sponges at the time of GnRH administration appeared to improve reproductive parameters.     

解冻期覆盖盐渍土地表对土壤盐分和水分的影响

选择春季土壤解冻期,用塑料薄膜、麦草和沙子覆盖盐渍土地面,改良盐碱地。结果表明,覆盖对土壤盐分表聚和水分蒸发损失具有明显的抑制作用。塑料薄膜采用全地面覆盖,麦草适用量为2934．8k／hm^2沙子的适宜覆盖厚度为4cm。     

Congenital spinal stenosis in beef calves in western Canada

Nineteen calves with a clinical history of posterior weakness or ataxia were examined at necropsy. Dorsoventral narrowing of the vertebral canal and myelopathy were found in the thoracic and lumbar areas of the spinal cord; vertebral metaphyseal growth plates had focal areas of premature closure. Malformation of the cranial base and hydrocephalus were also observed. Shortening of long bones and malformation of long bone epiphyses were prominent findings and were associated with focal premature closure of metaphyseal growth plates. The cause of these lesions is unknown; possible causes, including a maternal deficiency of manganese, are discussed.