小麦玉米秸秆全量还田对冬小麦出苗和光合生产的影响

以冬小麦品种烟农19为材料,研究小麦秸秆全量粉碎覆盖还田和玉米秸秆全量粉碎翻埋还田对冬小麦出苗和光合生产的影响。结果表明,小麦玉米秸秆连续全量还田可增加小麦的出苗数、出苗率和出苗均匀度,形成高产群体。播种过深和水分不足成为影响出苗的主要因素,秸秆阻碍对小麦出苗也有一定影响。小麦玉米秸秆连续全量还田提高了小麦的成穗数、群体干物质积累,同时也提高了叶片光合性能及群体的光合生产效率。小麦玉米秸秆连续全量还田主要促进了穗粒数的提高,穗数和千粒重也有所提高,进而显著提高了小麦籽粒产量。在本试验中小麦玉米秸秆两季连续全量还田处理对冬小麦出苗、光合生产以及产量的增加效应高于单季秸秆还田,玉米秸秆单季还田的增加效应高于小麦单季秸秆全量还田。     

丸化型水稻种衣剂对直播稻秧苗生长及酶活性的影响

为了给水稻种衣剂的进一步推广和发展提供理论依据,用自行研制的丸化型种衣剂(WHW-23)包衣水稻种子,通过田间直播试验,研究了丸化型水稻种衣剂对水稻秧苗生长及酶活性的影响.结果表明,丸化型水稻种衣剂具有促进种子萌发与秧苗生长,增强秧苗抗逆性和提高秧苗综合素质与成秧率等作用.与对照相比,包衣处理成秧率、根系活力和脯氨酸含量分别提高18.8%～24.9%,16.3%～25.5%和28.1%～60.0%;苗体过氧化物酶(POX)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性分别提高30.3%～33.9%,13.2%～23.1%和8.3%～23.2%.其综合效果优于对比试验所用的进口种衣剂.     

Nutritional Evaluation of a High-Oil Sunflower Meal in Broiler Starter Diets

Two experiments were conducted with broiler chicks to determine the nutritive value of high-oil sunflower meal (HO-SFM), a sunflower oil extraction by-product obtained through screw-press extraction and expanding processes with a proximate composition of 32% CP, 12% crude fiber, and 19% ether extract. In Experiment 1, the effects of a high level (46.4%) of HO-SFM on chick performance and gastrointestinal organs were tested. The objective of Experiment 2 was to determine if pelleting the feed could overcome the bulkiness resulting from inclusion of HO-SFM at a high level. The results of Experiment 1 indicated that addition of 46.4% HO-SFM to broiler starter diets significantly (P < 0.05) depressed body weight, feed intake, and gain but not feed conversion. Fat pad and liver lipid were again significantly (P < 0.05) decreased in the HO-SFM treatment. Impaired performance might have been due to the difference of the density of HO-SFM diet (608 g/L) compared with the soybean meal control (723 g/L). When bulkiness was overcome by pelleting in Experiment 2, it was found that pelleting the feed significantly enhanced growth of broiler chicks compared with SFM or soybean meal mash diets. Liver weights and lipid content were again decreased in HO-SFM diets. The results of this study suggest that HO-SFM can be used up to 28% without adverse effects on broiler chicks. Further improvement was observed with pelleting. Liver weight and lipid content were consistently reduced by feeding HO-SFM.     

Pelleting or Priming Seed with Calcium Improves Groundnut Seedling Survival in Acid Soils

A growth chamber experiment and a field experiment were conducted to investigate the effects of pelleting or priming groundnut seed with calcium (Ca), either as calcium sulfate (CaSO₄), calcium chloride (CaCl₂), calcium nitrate [Ca(NO₃)₂], calcium carbonate (CaCO₃) or Calcimax on growth of groundnut seedlings in acid soils. In the growth chamber experiment, Ca-treated and non-treated groundnut seeds were planted in acid-washed sand and watered with a dilute nutrient solution of pH 4.0 or 5.5. In the field experiment, the seeds were planted in an acid sand clay loam of pH [potassium chloride (KCl)] 4.8. Generally, pelleting or priming the seed with a Ca compound significantly reduced seedling mortality. Also, pelleting groundnut seed with Ca enhanced plant growth. An additional effect of priming was earlier emergence. The most effective Ca compound was CaSO₄ among the priming treatments, whereas CaCO₃ was the most effective among the pelleting treatments to reduce seedling mortality.     

Improved lime,phosphorus, and potassium recommendations based on double equilibration soil test methods for assessing buffering or fixation tendencies of individual soils

Abstract

This paper gives a perspective of papers published which led to the recommended two‐step methodologies of double equilibration soil test methods, identifies those persons contributing to development of the procedures, lists general conclusions reached regarding techniques, and gives details of steps involved in each of the double equilibration methods.     

化学疏花对欧李果实产量和品质的影响

试验以6年生‘农大4号’欧李为试材,于盛花期分别喷施不同浓度的3种疏花剂,测定植株坐果率、成熟期果实产量及糖酸含量。结果表明:喷施1.0 Be°石硫合剂可显著提高平均单果重和可溶性固形物含量,平均单枝果重和可滴定酸含量也有提高。喷施20 mg/L萘乙酸或10.0 g/L的施易乐效果较好。建议在欧李盛花期喷施1.0 Be°石硫合剂进行疏花。     

石灰和猪粪对铅锌尾矿土壤上光叶紫花苕生长的影响

通过温室盆栽,研究了改良剂石灰和猪粪对铅锌尾矿土壤上光叶紫花苕生长的影响。结果表明,施用改良剂能够使光叶紫花苕的株高、地上部鲜重、地下部鲜重、总鲜重、干重、根长、叶绿素a、叶绿素b、胡萝卜素含量均有所增加,施用猪粪条件下光叶紫花苕的株高、地上部鲜重、根长均显著高于对照,施用石灰条件下光叶紫花苕的株高、地上部鲜重、地下部鲜重、总鲜重、地下部干重、根长、叶绿素a含量、胡萝卜素含量均显著高于对照,说明施用石灰和猪粪能降低重金属对光叶紫花苕的毒害作用,促进其生长。     

Integrity of gastric mucosa in reared piglets – effects of physical form of diets (meal/pellets), pre‐processing grinding (coarse/fine) and addition of lignocellulose (0/2.5 %)

The aim of the present study was to investigate the potential effects of different particle fractions in non‐pelleted (meal) and pelleted diets on the development of pre‐ulcerative gastric alterations. Furthermore, the effect of increased crude fibre supply (lignocellulose) on the integrity of gastric mucosa were investigated. For that purpose, 49 piglets were divided into eight feeding groups and fed pelleted diets differing in grinding intensity (very coarse/coarse/fine/very fine) and addition of lignocellulose (0/2.5%) for 6 weeks. A coarsely ground meal was used as control diet. Mucosal integrity of the pars non‐glandularis was characterised by macroscopical and histological score and basal epithelial conductance. Feed structure was assessed by sieve analysis (wet/dry). The use of coarsely ground meal (25% >2 mm, 29% <0.4 mm) had almost no negative effects on the gastric wall: three of seven pigs had slight histological and none had macroscopical lesions. Irrespective of the original grinding intensity before pelleting, offering pelleted diets led to mucosal changes similar in severity (one out of seven pigs fed coarsely ground and pelleted diets had no macroscopical alterations, whereas all pigs fed finely ground and pelleted diets showed altered tissues). Increasing the proportion of coarse particles in the pellet (from 25 to 29% >2 mm) did not show any ulceroprotective effect. An increase of crude fibre content (42–54 g/kg dm) by adding lignocellulose did not result in a decreased ulcerogenity. Unpelleted diets are recommended as more favourable for alleviating the problem of gastric ulcers in pigs as the pelleting process is equal to a secondary grinding process. According to our results, an upper level of fine particles seems to be reasonable (a minimum level of coarse particles is not ulceroprotective). In this study, an amount of 30% <0.4 mm resulted in higher risks for ulcerations.     

玉米秸秆还田对砂姜黑土水分动态及冬小麦水分利用效率的影响

为给冬小麦水分高效利用提供科学依据,根据土壤-植物-大气连续体(SPAC)原理,利用野外小型蒸渗仪,以不施肥为对照(CK),原位研究了配方施肥(PF)以及配方施肥+秸秆还田(PF+JG)处理对砂姜黑土水分动态和冬小麦水分利用效率的影响.结果表明,秸秆还田主要影响0～40 cm土层土壤剖面水分含量,而40～80 cm土层土壤水分含量基本保持稳定.在小麦出苗期和拔节期,PF+JG处理的0～40 cm土层土壤含水量较PF处理分别提高50.9％和34.6％.土壤水分最大有效库容在小麦全生育期呈单峰变化趋势,峰值在返青期;PF+JG处理的出苗期土壤水分最大有效库容较CK和PF处理增加了8.25％和20.82％,拔节期增加8.07％和10.95％,且均差异显著(P＜0.05).PF+JG处理的土壤水分入渗量分别是CK和PF处理的4.53和3.55倍;小麦耗水量较PF处理降低9.2％;小麦产量和水分利用效率分别比CK和PF处理增加124.1％、18.8％和144.0％、30.8％,且差异达显著水平(P＜0.05).说明秸秆还田对冬小麦产量和水分利用效率的提高作用与增加土壤水分有效库容、水分入渗量和减少总耗水量有关.     

牛粪堆肥中添加石灰氮对堆肥发酵的影响

[目的]为了探讨石灰氮是否适合作为抑菌剂应用于堆肥化处理。[方法]采用静态堆肥系统,借助通风和翻堆等方式进行堆肥试验,测定堆肥过程堆料的物理性质、温度、水分、T-N、NH4+-N/NO3--N和大肠杆菌数量的变化,进一步研究堆肥中添加石灰氮对堆肥发酵的影响。[结果]在堆肥结束时对照大肠杆菌仍有残留,而各处理大肠杆菌迅速达到检出界限以下,但各处理组随着石灰氮添加量的增加堆体堆料氮素损失增多,且堆体达到腐熟所需的时间越长。[结论]在堆肥中添加石灰氮会延长堆肥时间,导致堆料氮素损失增多,但石灰氮作为一种杀菌效果良好的抑菌剂,如何合理地应用于堆肥化处理中有待于进一步研究。