POLICY REFORM AND PRODUCTIVITY CHANGE IN CHINESE AGRICULTURE: A DISTANCE FUNCTION APPROACH

Agricultural policy reform has been an important source of change in the Chinese agricultural sector. The reforms led to productivity growth and helped China in pursuing its self- sufficiency goal especially in the grain sector. To analyse whether observable productivity growth stems from technologically induced components, or from the market induced parts, a multi-input-multi-output model is derived using an econometric distance function framework. A decomposition allows to distinguish allocative effects, scale effects, technological change, and technical efficiency change. Data on farms in Zhejiang from 1986 to 1999 are used to analyse the impact of policy reform.Agricultural and Food Policy,

Policy Reform and Productivity Change in Chinese Agriculture: A Distance Function Approach

Agricultural policy reform has been an important source of change in the Chinese agricultural sector. The reforms led to productivity growth and helped China in pursuing its self-sufficiency goal especially in the grain sector. To analyse whether observable productivity growth stems from technologically induced components, or from the market induced parts, a multi-input-multi-output model is derived using an econometric distance function framework. A decomposition allows to distinguish allocative effects, scale effects, technological change, and technical efficiency change. Data on farms in Zhejiang from 1986 to 1999 are used to analyse the impact of policy reform.Productivity growth, China, Policy reform, Distance function, Productivity Analysis,

Thoughts on Breeding for Increased Forage Yield

Most forage crops have not experienced yield gains as impressive as those observed in annual grains crops such as maize (Zea mays L); in fact, yield improvement in lucerne appears to have stopped in the Midwestern USA (Riday and Brummer, 2002). I contend that much of this disparity can be explained by a failure of breeders to pursue long term recurrent selection programs within populations to capitalize on small, incremental improvements in yield over time. Many selection programs last only two or three cycles, resulting in a germplasm or cultivar release. Either no further selection is attempted or the new population is mixed with a larger germplasm pool in the belief that genetic variation is running low, a belief with little empirical support

Coccolithophore fluxes in the open tropical North Atlantic: influence of thermocline depth, Amazon water, and Saharan dust

Coccolithophores are calcifying phytoplankton and major contributors to both the organic and inorganic oceanic carbon pumps. Their export fluxes, species composition, and seasonal patterns were determined in two sediment trap moorings (M4 at 12 degrees N, 49 degrees W and M2 at 14 degrees N, 37 degrees W) collecting settling particles synchronously from October 2012 to November 2013 at 1200 m of water depth in the open equatorial North Atlantic. The two trap locations showed a similar seasonal pattern in total coccolith export fluxes and a predominantly tropical coccolithophore settling assemblage. Species fluxes were dominated throughout the year by lower photic zone (LPZ) taxa (Florisphaera profunda, Gladiolithus flabellatus) but also included upper photic zone (UPZ) taxa (Umbellosphaera spp., Rhabdosphaera spp., Umbilicosphaera spp., Helicosphaera spp.). The LPZ flora was most abundant during fall 2012, whereas the UPZ flora was more important during summer. In spite of these similarities, the western part of the study area produced persistently higher fluxes, averaging 241 x 10(7) +/- 76 x 10(7) coccoliths m(-2) d(-1) at station M4 compared to only 66 x 10(7) +/- 31 x 10(7) coccoliths m(-2) d(-1) at station M2. Higher fluxes at M4 were mainly produced by the LPZ species, favoured by the westward deepening of the thermocline and nutricline. Still, most UPZ species also contributed to higher fluxes, reflecting enhanced productivity in the western equatorial North Atlantic. Such was the case of two marked flux peaks of the more opportunistic species Gephyrocapsa muellerae and Emiliania huxleyi in January and April 2013 at M4, indicating a fast response to the nutrient enrichment of the UPZ, probably by wind-forced mixing. Later, increased fluxes of G. oceanica and E. huxleyi in October-November 2013 coincided with the occurrence of Amazon-River-affected surface waters. Since the spring and fall events of 2013 were also accompanied by two dust flux peaks, we propose a scenario in which atmospheric dust also provided fertilizing nutrients to this area. Enhanced surface buoyancy associated with the river plume indicates that the Amazon acted not only as a nutrient source, but also as a surface density retainer for nutrients supplied from the atmosphere. Nevertheless, lower total coccolith fluxes during these events compared to the maxima recorded in November 2012 and July 2013 indicate that transient productivity by opportunistic species was less important than "background" tropical productivity in the equatorial North Atlantic. This study illustrates how two apparently similar sites in the tropical open ocean actually differ greatly in ecological and oceanographic terms. The results presented here provide valuable insights into the processes governing the ecological dynamics and the downward export of coccolithophores in the tropical North Atlantic.Netherlands Organization for Scientific Research (NWO) [822.01.008]; European Research Council (ERC) [311152]; University of Bremen; European Union [600411]info:eu-repo/semantics/publishedVersio

Dietary calcium decreases but short-chain fructo-oligosaccharides increase colonic permeability in rats

An increased intestinal permeability is associated with several diseases. Nutrition can influence gut permeability. Previously, we showed that dietary Ca decreases whereas dietary short-chain fructo-oligosaccharides (scFOS) increase intestinal permeability in rats. However, it is unknown how and where in the gastrointestinal tract Ca and scFOS exert their effects. Rats were fed a Western low-Ca control diet, or a similar diet supplemented with either Ca or scFOS. Lactulose plus mannitol and Cr-EDTA were added to the diets to quantify small and total gastrointestinal permeability, respectively. Additionally, colonic tissue was mounted in Ussing chambers and exposed to faecal water of these rats. Dietary Ca immediately decreased urinary Cr-EDTA excretion by 24 % in Ca-fed rats compared with control rats. Dietary scFOS increased total Cr-EDTA permeability gradually with time, likely reflecting relatively slow gut microbiota adaptations, which finally resulted in a 30 % increase. The lactulose: mannitol ratio was 15 % higher for Ca-fed rats and 16 % lower for scFOS-fed rats compared with control rats. However, no dietary effect was present on individual urinary lactulose and mannitol excretion. The faecal waters did not influence colonic permeability in Ussing chambers. In conclusion, despite effects on the lactulose: mannitol ratio, individual lactulose values did not alter, indicating that diet did not influence small-intestinal permeability. Therefore, both nutrients affect permeability only in the colon: Ca decreases, while scFOS increase colonic permeability. As faecal water did not influence permeability in Ussing chambers, probably modulation of mucins and/or microbiota is important for the in vivo effects of dietary Ca and scFOS

Effects of Chloride Fertilization on Alfalfa Cation-Anion Content

Producing low potassium (K) forages has increased due to demand for such forages in the dairy business. In the month prior to calving, a fairly anionic diet is recommended in dairy cows to avoid milk fever, a term used for hypocalcemia, a deficiency in plasma calcium (Ca) at the onset of lactation in dairy cows. This bovine disease affects approximately 6 to 8% of all U.S. dairy cows annually, directly costing the dairy industry up to $200 million/year. As dairy cows enter the lactation stage prior to calving, large amounts of calcium leave the blood and enters milk faster than it can be replaced. This decreased calcium concentration in the blood lowers the pH, causing nerve disorders, muscle weakness, loss of appetite, paralysis, and subsequent death if not treated immediately. Treatment typically includes an intravenous dosage of a calcium solution, usually including a mixture of phosphorus (P), K, magnesium (Mg) and dextrose. Cationic diets, such as forages high in potassium (\u3e2.5%) are meant for the post-calving, lactation stage because of the dairy cow’s diet requirement in producing milk

Prospects for Improving Alfalfa Yield Using Genomic- and Phenomic-Based Breeding

Alfalfa (Medicago sativa L.) is a perennial outcrossing legume that is cultivated as an important forage crop in many parts of the world. Yield is the most important trait for profitable alfalfa production, yet over the last 30 years yield improvement in California has stagnated. Current breeding methods focus on recurrent phenotypic selection; however, alternatives incorporating genomic- and phenomic-based information may enhance genetic gain and help to address the lack of yield improvement. Here we attempt to increase the yield potential of alfalfa using genomic selection (GS) in combination with high throughput phenotyping (HTP). A total of 193 families from two closely related elite populations were sown in the greenhouse and transplanted into mini sward plots at two locations near Davis, CA in May 2020. The trial was managed as a high-input system under full irrigation. Families were genotyped and phenotyped for biomass yield by mechanical harvest and a combination of drone and tower-based remote sensors across 12 harvests, 3 in the establishment year (2020), 7 in the first full year of production (2021) and 2 in 2022. Alfalfa yields ranged from 13-27 tonnes DM/hectare/year with a number of half-sib families outperforming popular cultivars in the first 2 years of production. Biomass volume predicted from the drone-based cameras had a moderate prediction accuracy with an overall R2 of 0.55. Some individual harvests reached accuracies as high as 0.85. Genotyping resulted in a dataset with 6,838 SNPs. Allele frequencies were used to generate a relationship matrix for GS. Narrow-sense heritability for dry matter yield was 0.31 and the predictive ability of the GS model was 0.15