Effect of adding Lactobacillus plantarum and soluble carbohydrates to swine manure on odorous compounds, chemical composition and indigenous flora

Manure odor, which results in the increasing complaints and lawsuits, has increased the tension among swine producers and surrounding residents. The effects of Lactobacillus plantarum and different rates of soluble carbohydrates additions to swine manure on odorous compounds, chemical compounds and indigenous flora were evaluated. Additions were calculated on dried manure weight basis. Variables monitored included ammonia （NH3）, hydrogen sulfide （H2S）, odor offensiveness, pH, ammonium nitrogen（NH4^＋-N）, volatile fatty acids （VFAs）, urease and indigenous flora. The results indicated that the combination of L. plantarum and soluble carbohydrates dramatically reduced manure pH. Lower pH resulted in the reduction of NH3 volatilization （34.6%-92.4%, P〈0.01）, the increases of H2S （P〈 0.05） and NH4^＋-N （5.3%-17.5%, P〈0.05）. In addition, L. plantarum and soluble carbohydrates additions significantly reduced odor offensiveness, those VFAs related to malodor indicators（valeric acids, 12.3%-47.7%, P〈 0.05; iso-valeric, 3.5%-23.8%） and the main microorganisms responsible for odor production, with the number of Eubacteria in swine manure reducing by 4.9%, 11.6%, 17.4%, 34.1% and 32.2% respectively.

Accumulation and Distribution Dynamics of Soluble Carbohydrate in Helianthus tuberosus under Drought Stress

With Qingyu 1 and Qingyu 2 as test materials, variation of soluble carbohydrate content in different parts were studied under two types of artificially simulated drought stress （polyethylene glycd PEG-6000 stress and water-controlling stress）. The results showed that under the stress of PEG, soluble carbohydrate content in leaves of Qingyu 1 and Qingyu 2 increased with the prolonging time of stress; soluble carbohydrate content in stems of Qingyu 1 did not show regular changes with the prolonging time of stress, while 30% PEG stress received the best effect on Qingyu 2 after 24 h; soluble carbohydrate content in roots of Qingyu 1 and Qingyu 2 increased with the prolonging time of stress. Under different intensities of water-controUing stress, soluble carbohydrate content in leaves of Qingyu 1 first increased then decreased, while that in leaves of Qingyu 2 increased; soluble carbohydrate content in stems of Qingyu 1 and Qingyu 2 increased with the pro- longing time of water-controlling stress; soluble carbohydrate content in roots of Qingyu 1 decreased with the prolonging time of water-contmlling stress, while that in roots of Qingyu 2 differed slightly.

Variation of carbon partitioning in newly expanded maize leaves and plant adaptive growth under extended darkness

Plants must maintain a balance between their carbon(C)supply and utilization during the day–night cycle for continuous growth since C starvation often causes irreversible damage to crop production.It is not well known how C fixation and allocation in the leaves of crops such as maize adapt to sudden environmental changes.Here,to quantify primary C fixation and partitioning in photosynthetic maize leaves under extended darkness and to relate these factors to plant growth,maize seedlings were subjected to extended darkness(ED)for three successive days at the 6 th leaf fully expanded stage(V6).ED reduced plant growth and leaf chlorophyll levels but not the rate of net CO_2 exchange.As a result of the reduction in photoassimilates,the accumulation of starch and total soluble carbohydrates(TSC)in mature leaves also decreased under ED.However,the percentage of the daily C fixation reserved in mature leaves increased.These transient C pools were largely composed of TSC and were mainly used for consumption by increased nocturnal respiration rather than for transport.As the days went on,both the amount of C accumulated and the percentage of the daily fixed C that was reserved in leaves decreased,which could be largely accounted for by the attenuated starch synthesis in all treatments.The activities of ADPglucose pyrophosphorylase and soluble starch synthase decreased significantly over time.Therefore,this study concluded that both starch and TSC are involved in the coordination of the C supply and plant growth under a sudden C shortage but that they may be involved in different ways.While the ratio of reserved C to daily fixed C increased to maintain blade function under acute C starvation,both the amount and the proportion of C reserved in mature leaves decreased as plant growth continued in order to meet the growth demands of the plant.

Transformation of Sucrose to Starch and Protein in Rice Leaves and Grains under Two Establishment Methods

Six rice varieties, PR120, PR116, Feng Ai Zan, PR115, PAU201 and Punjab Mehak 1 were raised under aerobic and transplanting conditions to assess the effects of planting conditions on sucrose metabolising enzymes in relation to the transformation of free sugars to starch and protein in flag leaves and grains. Activities of sucrose synthase, sucrose phosphate synthase and acid invertase increased till flowering stage in leaves and mid-milky stage（14 d after flowering） in grains and thereafter declined in concomitant with the contents of reducing sugar. Under aerobic conditions, the activities of acid invertase and sucrose synthase（cleavage） significantly decreased in conjunction with the decrease in non-reducing sugars and starch content in all the varieties. Disruption of starch biosynthesis under the influence of aerobic conditions in both leaves and grains and the higher build up of sugars possibly resulted in their favoured utilization in nitrogen metabolism. Feng Ai Zan, PR115 and PR120 maintained higher levels of sucrose synthase enzymes in grains and leaves and contents of metabolites（amino acid, protein and non-reducing sugar） under aerobic conditions, while PR116, Punjab Mehak 1 and PAU201 performed better under transplanting conditions, thus showing their adaptation to environmental stress. Yield gap between aerobic and transplanting rice is attributed primarily to the difference in sink activity and strength. Overall, it appear that up-regulation of sucrose synthase（synthesis） and sucrose phosphate synthase under aerobic conditions might be responsible in enhancing growth and productivity of rice varieties.

Cultivation Systems Using Vegetation Cover Improves Sustainable Production and Nutritional Quality of New Rice for Africa in the Tropics

Little is known about the impact of direct sowing under vegetation cover on the production and quality of New Rice for Africa （NERICA） on poor oxisol. In this study, two NERICA varieties （NERICA 3 and NERICA 8） were grown under tropical oxisol soil with very low nutrient contents. Four cultivation systems were used in completely randomized block design, including plowing （control）, unplowed soil with dead vegetation cover （DVC）, unplowed soil with live vegetation cover （LVC） and unplowed soil with mixed vegetation cover （MVC）. DVC significantly improved the exponential growth of NERICAs. NERICA 3 was the more productive （2.16–3.05 t/hm2） compared with NERICA 8 （0.71–1.21 t/hm2）. Cultivation systems improved the nutritional quality of NERICAs. The total protein content of NERICA 3 under DVC and MVC was 84.8% and 75.0% higher than control, respectively. The total soluble carbohydrate contents of NERICA 8 under LVC and MVC was 73.2% and 57.3% higher than control, respectively. These results suggested that conservative approach like direct sowing on unplowed soil with vegetation cover systems can improve the nutritional quality of rainfed NERICAs and their sustainable production under poor oxisol soil in sub-Saharan Africa.

Effect of planting date and nitrogen fertilization on photosynthesis and soluble carbohydrate contents of cotton in relation to silverleaf whitefly （Bemisia tabaci biotype “B”） populations

The impacts of planting date and nitrogen fertilization on cotton （Gossypium hirsutum L.） photosynthesis and soluble carbohydrate contents in relation to silverleaf whitefly, Bemisia tabaci （Gennadius） biotype “B”, populations were examined in field experiments. Cotton planted in late April and early June was treated with 0, 112, 168 and 224 kg/N hectare in soil using urea fertilizer. The mean photosynthetic rate of April-planted cotton was 4%-20% higher than that of June-planted cotton early in the season, but 10%- 18% lower than that of June-planted cotton late in the season. The photosynthetic rates for both planting dates were positively correlated with levels of added nitrogen. While levels of glucose for both planting dates were positively correlated with nitrogen levels, fructose and sucrose levels were not. The mean levels of fructose were up to 40% lower, while that of sucrose were up to 59% higher, in April-planted cotton than in June-planted cotton. Levels of photosynthetic rate or stomatal conductance were not correlated with adult whitefly densities for either planting date. Levels of glucose and fructose were positively correlated with whitefly densities only for June-planted cotton late in the season.