Zinc uptake and distribution in tomato plants in response to foliar supply of Zn hydroxide‐nitrate nanocrystal suspension with controlled Zn solubility

The present study investigated the foliar uptake rate, distribution, and retranslocation patterns of novel, synthesized zinc hydroxide‐nitrate nanocrystals (ZnHN; solubility 30–50 mg Zn L^?1) applied on to the adaxial surface of tomato leaves (Solanum lycopersicum L. cv. Roma). The total Zn absorption from ZnHN suspension positively increased with ZnHN application rates, but the relative efficacy started to decline at > 400 mg Zn L^?1. Within the 3 weeks, total Zn recovery in the ZnHN‐treated plants was 16% of the total ZnHN‐Zn applied, compared to the near 90% total Zn recovery in the Zn(NO₃)₂‐plants at the same Zn rate. Foliar‐absorbed ZnHN‐Zn was distributed from the treated leaves into other plant parts and preferentially translocated into the roots. Distribution of Zn from ZnHN‐treated leaves to apical parts was not limited by Zn deficiency. These results demonstrate that ZnHN crystals with controlled solubility provided some sort of slow‐release Zn over a certain growth period at a rate slower (but quantitatively effective) than the soluble Zn(NO₃)₂. The efficacy of the prolonged foliar Zn supply could be enhanced if the ZnHN suspension is sprayed over a large leaf surface area at the peak vegetative or early flowering stage.     

Improvement of biogas production from oil palm empty fruit bunches (OPEFB)

Oil palm empty fruit bunches (OPEFB), a waste lignocellulosic material, which is the main byproduct of vegetable oil production industries in Indonesia and Malaysia, was utilized as a source for biogas production. Pretreatments using NaOH as well as phosphoric acid were investigated to improve the biogas production. Clear positive effects of the pretreatments on the yield of methane were observed. The best improvement was achieved when 8% NaOH for 60 min was used for the pretreatment, which resulted in 100% improvement in the yield of methane production. In addition, treatment with phosphoric acid resulted in 40% improvement in the methane yield compared with that of the untreated material. The results showed that the carbohydrate content of OPEFB could be efficiently converted to methane under the anaerobic digestion process. 97% of the theoretical value of methane production was achieved after the pretreatment with NaOH for 60 min. Moreover, the initial rate of methane production was also increased by more than 85% after the treatment with NaOH compared with that of the untreated OPEFB.     

竹炭制备高比表面积活性炭及其电容性质研究

[目的]研究竹炭制备高比表面积活性炭及其电容性质。[方法]采用竹材加工剩余物制成的竹炭为原料,以氢氧化钾为活化剂制备了双电层电容器用活性炭,并通过正交试验研究了液固比、活化温度、活化时间及升温速率对产品吸附性能的影响。[结果]得到最优的活化工艺参数如下：碱炭比为4∶1,活化温度为770℃,活化时间为60 min,升温速率为10℃/min,比表面积高达2 379 m2/g,但其质量比电容不是最大。当比表面积为2 121 m2/g时,质量比电容最大（323 F/g）,但其体积比电容偏小。[结论]为研制高比电容量且具有实际应用价值的电极材料提供了依据。     

碱法提取五常稻花香大米淀粉工艺优化

以五常稻花香2号大米为原料,优化碱法提取大米淀粉的工艺,并利用差示扫描量热仪测量大米淀粉的热力学特性.结果表明,当料液比1∶7,氢氧化钠添加量0.5％,水解温度40℃,水解时间2h时,蛋白质残留率为0.43％.     

Liming and Boron in a Teak Crop Established during Early Stages in an Acid Soil

Cultivation of a teak crop in acid soils needs adequate agronomic management of these characteristics of high acidity and low nutrient supply to obtain high yields in wood. This work evaluated the effect of liming and application of boron in teak plants during early stage of growth in acid soils from Córdoba, Colombia. The experiments were conducted in the greenhouse and soils laboratory of the Faculty of Agricultural Sciences by using acid soil limed with calcium hydroxide (Ca(OH)₂) and fertilized with boron. The treatments were chosen according to the Box Bernard augmented matrix 3, with dosages of Ca(OH)₂ from 300 to 5700 kg ha^?1 and boron from 0.3 to 5.225 kg ha^?1, using three repetitions per treatment. Data obtained on boron in the soils (Bs) and in the plant (Bp), foliar area (AF), leaf dry mass (MSH), and roots (MSR) were analyzed through means tests and regressions from response surfaces (p ≤ 0.05). The results indicated increased pH and in the soil’s exchangeable calcium (Ca). To reach the maximal AF, the dosages of 2.26 kg ha^?1 of boron (B) and 4522.6 kg ha^?1 of Ca(OH)₂ were estimated; for MSH, stem, and roots boron, dosages ranged between 2.02 and 5.225, with the dosage of 5700 kg ha^?1 of Ca(OH)₂ in all the variables evaluated. Application of calcium hydroxide also showed positive effect in leaf, stem, and MSR gain of teak seedlings during early growth stages. Fertilization with boron (B) did not show significant effect upon growth of dry masses of the parts evaluated.     

水溶液体系中Ca(OH)_2和FeSO_4的除磷效应

为了解决人工湿地冬季除磷效果减弱的问题,试验选取了Ca(OH)_2和FeSO_4作为辅助除磷试剂,考察了水溶液体系中两者的除磷效应。结果表明:Ca(OH)_2和FeSO_4均具有较好的除磷效果,单独使用时Ca(OH)_2要优于FeSO_4,但单独使用会显著改变体系的p H值,破坏人工湿地的生态环境。采用Ca(OH)_2与FeSO_4的合理配比和先添加Ca(OH)_2再施用FeSO_4的顺序,不仅可极大地提高磷的去除率,还可以有效地调节系统溶液的酸碱度至中性,从而保持人工湿地生态系统的稳定性。本研究结果为强化人工湿地除磷提供了新方案和基础数据。     

尿素与氢氧化钙不同组合对麦秸纤维含量的影响

为探讨尿素和氢氧化钙不同组合对麦秸纤维含量的影响,将不同添加量的尿素和氢氧化钙(分别为麦秸干质量的0%、2%、3%和4%)按照不同的组合添加,共16个组(原麦秸组为对照组,其余15个组为试验组),通过测定各组麦秸的中性洗涤纤维和酸性洗涤纤维含量来确定尿素和氢氧化钙最适宜的组合。结果表明:15个试验组的中性洗涤纤维含量极显著低于对照组(P<0.01),其中,2%尿素+2%Ca(OH)2组(0.55%)比对照组降低33.73%(P<0.01)。酸性洗涤纤维含量,2%尿素组、3%尿素组及2%尿素+4%Ca(OH)2组与对照组差异不显著(P>0.05),3%尿素+2%Ca(OH)2组(0.41%)显著低于对照组(P<0.05),其余试验组均极显著低于对照组(P<0.01),其中,2%尿素+2%Ca(OH)2组(0.30%)比对照组降低30.23%(P<0.01)。大部分试验组在2种纤维含量上也存在极显著或显著的差异(P<0.01或P<0.05)。在所设定的试验条件下,2%尿素+2%Ca(OH)2的组合降低麦秸纤维含量效果最佳。     

3种常用杀菌剂对不同来源木薯细菌性萎蔫病菌的毒力测定

细菌性萎蔫病是世界范围内木薯种植中的重要病害,但防控技术研究较少。采用含毒介质法评价了3种常用杀菌剂对不同来源的29个病菌菌株的抑菌作用。结果表明,供试菌株对净刹(80%乙蒜素EC)和农用硫酸链霉素(72%硫酸链霉素SP)敏感性较高,而对可杀得贰仟(53.8%氢氧化铜WG)表现出不同程度的抗性。建议生产中使用乙蒜素和硫酸链霉素对该病进行防治。     

水稻秸秆预处理对猪粪高温堆肥过程中磷素形态变化的影响

[目的]明确秸秆预处理加快堆肥效率的同时,考察其是否能对堆体中磷的转化产生影响。[方法]通过添加秸秆腐熟剂(B)和氢氧化钙(C)分别对水稻秸秆进行10 d(B1、C1)和20 d(B2、C2)的预处理静态堆置,以无预处理的秸秆为对照(CK),与猪粪按比例混合后进行好氧堆肥。用红外光谱(IR)、扫描电镜(SEM)和X射线衍射(XRD)分析了水稻秸秆的改变程度,并用传统方法分级测定了堆肥过程中连续浸提的磷形态。[结果]秸秆腐熟剂预处理对秸秆结构破坏性更强,且预处理时间越长效果越好。秸秆腐熟剂预处理可缩短堆肥高温期,促进水稻秸秆与猪粪混合堆肥的进程,而氢氧化钙预处理则并无明显效果。堆肥结束后,C1和C2的总磷含量分别为26.47和23.68 g/kg,CK为22.51 g/kg;而B1和B2处理分别高达29.84和32.88g/kg。不同处理堆体中各形态磷含量差异较大,但整体来看各形态总磷含量高低依次为HCl-P>NaHCO3-P>H2O-P>NaOH-P。从植物有效磷(H2O-P+NaHCO3-P)含量上来看,秸秆腐熟剂预处理效果要优于氢氧化钙预处理(B1和B2分别为14.44和13.74 g/kg,C1和C2分别为12.27和12.02 g/kg)。不同的秸秆预处理时间对堆肥过程中磷素形态的转变影响不大,但与氢氧化钙预处理组相比,秸秆腐熟剂预处理更有利于NaOH-Po向NaOH-Pi的转化。[结论]秸秆腐熟剂对水稻秸秆进行预处理破坏性强于氢氧化钙预处理,且预处理时间越长效果越好。预处理有利于促进秸秆、猪粪混合堆肥过程中磷植物有效性的提高,且秸秆腐熟剂预处理效果要优于氢氧化钙预处理。     

68个去皮和带皮豆粕的常规营养、脲酶活性及蛋白质溶解度比较研究

采集来源于美国、巴西、中国的11个去皮豆粕和中国51个大、中、小型企业加工的57个带皮豆粕，有代表性地比较其营养和品质。结果显示：去皮豆粕优于带皮豆粕，去皮豆粕的粗蛋白质、总能值、蛋白质溶解度（在0．2％KOH溶液中）分别为46．72％、17．11MJ／kg、81．31％，分别比带皮豆粕高1．64％、0．03MJ／kg和12．88％（P〈0．01）；而粗纤维和NDF含量分别为3．49％和7．74％，比带皮豆粕低1．16％和2．19％（P〈0．05）。对相同大豆来源、相同工艺的4个配对去皮和带皮豆粕进行比较，去皮加工使豆粕的粗蛋白质、总能值和蛋白质溶解度分别提高2．34％、0．08MJ／kg和4．14％；使粗纤雏和NDF分别降低0．93％、1．19％。去皮工艺改善了豆粕的营养和品质，粗蛋白质、粗纤雏、NDF、总能值和蛋白质溶解度是反映去皮工艺对豆粕营养品质影响的敏感指标。