Interaction Effects of Nitrogen and Phosphorus on Nodulation in Red Clover (Trifolium pratense L.)

Red clover (Trifolium pratense L.) is one of the most important plants in forage production, especially in northern areas. Fertilisation practices are focused on high yield and forage quality but effects of nutrients on nodulation and N₂ fixation are poorly understood. The aim of this work was to study how nitrogen (N) and phosphorus (P) separately as well as in combination affected nodulation. Red clover plants were grown in pots with gravel in a greenhouse for 11 weeks. To resemble field conditions the root temperature was kept lower than the shoot temperature. Plants were given five different combinations of N and P concentrations during growth. The result showed that at high N concentrations P had a counteracting effect on the N inhibition. The N₂-fixation parameters, nodule number, nodule dry matter and specific nitrogenase activity, were six times higher in plants grown with high N and high P than in plants with high N and low P. When the N₂-fixation parameters and the dry matter of roots and shoots were related to total plant dry matter, there was a stronger effect of P on nodulation parameters than on roots and shoots. This indicates that P has a direct effect on the N₂-fixation parameters, rather than an indirect effect via increased plant growth. These results demonstrate the importance to studying the effects of more than one nutrient at a time.     

Effect of sowing methods and sowing rate in organic seed production of timothy (Phleum pratense L.), meadow fescue (Festuca pratensis Huds.) and red clover (Trifolium pratense L.)

Different sowing methods and sowing rates were evaluated in organic seed production of timothy (two trials), meadow fescue (two trials) and red clover (one trial) in Southeast Norway, during 2010–2013. The plan included: (1) broadcast sowing of grass/clover, cover crop sown at 12 cm row distance; (2) sowing of cover and seed crop in crossed rows, both at 12 cm row distance; and (3) sowing of cover crop and seed crop in every other row. The three sowing rates were 5, 10 and 15 kg ha–1 in timothy and meadow fescue and 3, 6 and 9 kg ha–1 in red clover. On average for sowing rates and all trials with timothy, meadow fescue and red clover, first year’s seed yields were 5–6%, 20–25% and 19–25% higher on plots sown with cover crop and seed crop in every other row than on plots where seed crop had been broadcast or sown perpendicularly to the cover crop. The different sowing methods had no effect on weed coverage or weed contamination in the cleaned seed. Increasing sowing rate usually had a negative influence on seed yield, while weed coverage/contamination was not significantly affected. It is concluded that organic seed crops should be established with cover crop and seed crop in every other row at a low sowing rate. However, in an organic production system, even this favorable method will not always be sufficient to meet the requirement for seed crop purity.     

紫云英与有机物料连续还田在黄泥田水稻稳产提质增效中的作用

为明确紫云英与不同有机物料还田在黄泥田改土培肥与水稻化肥减量增效中的作用，基于连续11a定位试验，研究了不施肥(T₀,CK)、单施化肥(T₁)、仅翻压紫云英(T₂)、紫云英与水稻秸秆联合还田(T₃)、紫云英与牛粪配施还田(T₄)，以及紫云英与水稻秸秆联合还田+40%化肥(T₅)处理对水稻产量、籽粒营养品质及稻田肥力的影响。结果表明，与CK相比，各施肥处理籽粒历年平均产量增幅11.4%～21.0%，秸秆平均产量增幅17.1%～40.2%，差异均显著；其中以T5提升尤为明显，其籽粒产量与秸秆产量较T1分别提高3.4%和6.6%；有效穗是产量差异的重要性状因子。各施肥处理成熟期植株地上部氮、磷、钾吸收量较CK分别增幅14.3%～30.6%、8.9%～32.7%、2.9%～47.2%，其中氮、磷吸收量以T₄最高，钾吸收量以T₅最高。与CK相比，第10年施肥处理籽粒氨基酸总量增幅11.5%～20.6%，必需氨基酸增幅11....     

Effect of Sulfur and Boron Nutrition on Yield and Quality of Soybean (Glycine max L.) Grown in an Acid Soil

Soybean (Glycine max L.), being a leguminous oilseed crop, requires relatively higher amount of sulfur (S) and boron (B) for optimum yield and quality. A field experiment was conducted to evaluate the effect of S and B application on growth, yield, and quality of soybean, and to find out their optimum doses for the best crop performance in acidic soils of northeast India. The treatments comprised four levels of S (0, 20, 40, and 60 kg/ha) and four levels of B (0, 0.5, 1.0, and 1.5 kg/ha) in factorial combination. In general, application of S and B, either alone or in combination, significantly increased the growth, yield, and quality of soybean. When applied alone, S resulted in best yield (1767 kg/ha) at S₄₀, which was 21.2% higher than the yield at control (1458 kg/ha), while B produced maximum yield (1578 kg/ha) at B_1.5 (8.23% higher than control). Interestingly, 57.4% yield improvement over control was recorded with combined application of S₄₀ and B_1.5, which shows their synergistic effect on crop performance. Similarly, with concurrent application of S₄₀ and B_1.5, a 28% increase in protein and 33% increase in oil content of soybean were recorded relative to control. In general, S₄₀ + B_1.5 also resulted in the highest nutrient nitrogen, phosphorus, potassium sulfur, and boron (NPKSB) uptake by soybean. Based on these results, we recommend the conjunctive use of 40 kg S and 1.5 kg B/ha for the best yield and quality of soybean on acidic soils of northeast India and other regions with similar soils.     

连续施用有机肥对菜田土壤Cu和Zn积累及辣椒产量品质的影响

采用田间随机区组试验,研究了不同用量鸡粪和猪粪有机肥(0,15,30,45和60 t/hm^2)施用后,重金属Cu和Zn在土壤剖面迁移积累特征,及辣椒产量、品质和各器官(根、茎、叶和果实)Cu和Zn含量的变化。结果表明,鸡粪和猪粪施用显著增加了耕层(0—20 cm)土壤Cu和Zn含量,与对照相比,Cu含量增幅分别达到22.60%~66.59%和36.13%~95.00%,Zn含量增幅分别达到10.49%~39.27%和11.18%~51.94%,猪粪施用后耕层(0—20 cm)土壤Cu和Zn含量增幅大于鸡粪;鸡粪和猪粪带入的Cu和Zn主要积累在耕层(0—20 cm)土壤,Cu和Zn含量最高分别为36.95,137.24 mg/kg,尚未超出国家安全标准。高用量(60 t/hm^2)鸡粪和猪粪中的Cu和Zn存在明显向土壤深层迁移现象,与猪粪处理相比,鸡粪中带入的Cu和Zn向下迁移的幅度小。鸡粪和猪粪施用显著提高了辣椒果实单果重及产量,在施用量为30 t/hm^2时达到最大,产量比对照分别增加24.98%和29.04%,高用量(60 t/hm^2)鸡粪和猪粪显著提高了辣椒Vc含量、蛋白质含量和可溶性糖含量,降低了硝酸盐含量,改善了辣椒品质。15 t/hm^2鸡粪和60 t/hm^2猪粪显著提高了辣椒果实Cu含量,但均未超过20 mg/kg,可以安全食用。鸡粪和猪粪的施用对果实Zn含量(16.35~20.87 mg/kg)影响不显著。可以认为,合理施用鸡粪和猪粪有机肥在短期内能够改善土壤性质,提高作物产量和品质,虽然会造成Cu和Zn在耕层(0—20 cm)土壤的积累,但尚未引起土壤Cu和Zn污染,也不影响辣椒果实的安全食用,但如果长期施用则有必要进行进一步监测。     

化肥减量配合紫云英还田对双季稻产量及氮肥利用率的影响

旨在明确化肥减量条件下不同紫云英还田量对亚热带双季稻区早、晚稻产量及氮肥利用率的影响。以双季稻种植模式为研究对象,设置2个不同的减肥量处理配施不同的紫云英还田量,观察紫云英连续还田下不同处理对双季稻产量和养分利用率的影响。结果表明:与常规施肥处理(100%F)相比,20%减肥量各处理的早稻产量均得到显著提高,增产幅度为5.0%～13.2%;40%减肥量条件下,配施15 000～22 500 kg/hm~2紫云英早稻产量不减产,而配施30 000～37 500 kg/hm~2紫云英后早稻产量有显著提高,增产幅度为5.4%～8.5%。各减肥配施紫云英处理的晚稻产量均随紫云英还田量的增加而升高(P0.05)。各减肥配施紫云英处理早稻化学氮肥的农学利用率、偏生产力及回收率均较常规施肥处理显著提高,但晚稻的氮肥利用率无显著差异。将紫云英还田输入的氮纳入总氮素投入后,早稻总氮素的农学利用率和回收率均随紫云英还田量的增加而降低;与100%F相比,各减肥配施紫云英处理的农学利用率未显著降低,但紫云英还田量达到37 500 kg/hm~2及以上时会导致早稻的氮素回收率显著降低。各紫云英还田处理土壤全氮含量均高于100%F(P0.05),且土壤速效氮含量均显著高于100%F处理(P0.05)。亚热带双季稻种植模式下,长期紫云英还田配合减量施肥对早、晚稻产量和氮肥利用率均产生正面效应,且能提高土壤有机质含量和全氮含量,土壤速效氮含量显著高于常规施肥处理。因此,适量紫云英还田配施化肥除可减少化肥用量外,也是亚热带双季稻区兼顾提升稻米产量和培肥土壤的有效技术。本试验条件下,化肥减量40%配合22 500～30 000 kg/hm~2紫云英的配比综合效果较好。     

Influence of Spent Mushroom Compost (SMC) as an Organic Fertilizer on Nutrient,Growth, Yield,and Essential Oil Composition of German Chamomile (Matricaria Recutita L.)

To investigate the effect of Spent Mushroom Compost (SMC) as an organic fertilizer on German chamomile (Matricaria recutita L.) nutrient, growth, yield, essential oil and osmolytes a greenhouse experiment was conducted through a randomized complete design in six replications. A mixture of sandy loam soil with 5, 10 and 15% volume rates of spent mushroom compost was used as the partial substrate for German chamomile pot culture. Finding of results revealed that usage of SMC in the growing media increased significantly plant growth, flower yield, essential macro nutrient uptake, sodium concentration, proline and soluble sugars content as well as essential oil percentages in compared to control. Comparison between the treatments indicated that addition of 10% SMC to the plant soil substrate cause to higher growth and addition of higher rates of SMC (10% and 15%) led to better yield. The obtained results showed that absorption of K and Na enhanced significantly by increasing of SMC percentage in growing media but there was no significant difference in N and P uptake in SMC treatments. The results of GC and GC-MS analysis presented that the main compositions of essential oil extracted from German chamomile flowers accounted for 83.99–99.84% of total essential oil in SMC treatments. Regarding important role of SMC on the essential oil yield, we can consider SMC could be a suitable substitute for chemical fertilizers as environmentally friendly material in cultivation medicinal plant German chamomile.     

Comparative Efficacy of White Mustard (Sinapis alba L.) and Soybean (Glycine max L. Merr.) Seed Meals as Bioherbicides in Organic Broccoli (Brassica oleracea Var. Botrytis) and Spinach (Spinacea oleracea) Production

White mustard and soybean seed meals were compared for weed control and yield of organically grown broccoli and spinach. The meals were incorporated into the soil 2 weeks before crop planting at two rates (1.24 and 4.48 t ha^?1). Weed densities and hand-weeding time were recorded twice during the growing seasons and weed biomass was measured at crop harvest. Compared to the 1.24 t ha^?1 soybean treatment, weed densities were 52 to 95% and 41 to 45% less at 3 and 6 weeks after planting, respectively, in both crops with the 4.48 t ha^?1 white mustard seed meal treatment. Time required for hand weeding at these times was also reduced by up to 82% and 48%, respectively. Broccoli yield was similar in all the treatments, but spinach yield was greatest in the 4.48 t ha^?1 treatments for both seed meals. Petiole nitrate and nutrient concentrations in both crops were generally similar in all the treatments.