稻草型生物有机肥对茄子产量与品质的影响

为推广应用稻草型生物有机肥,采用田间小区试验研究了稻草型生物有机肥对茄子产量、品质及其根系特性的影响。结果表明:稻草型生物有机肥显著提高了茄子的产量,增加了茄子中维生素C、可溶性糖含量,降低了茄子中硝酸盐和亚硝酸盐含量,增强了茄子生育中后期的根系活力,提高了茄子根系硝酸还原酶的活性。     

渭北旱塬不同程度土壤侵蚀及生产力恢复试验

土壤侵蚀会降低生产力,影响作物产量,因此,恢复土壤生产力是人们普遍关注的问题。采用人工模拟土壤侵蚀方法,对侵蚀状况下的土壤进行生产力研究,并配以施肥探索土壤生产力的恢复情况。结果显示：I）施肥可以改善土壤的物理性状,侵蚀土壤的含水量降低,密度增加,孔隙度减小;2）在无肥下,土壤中有机质及其他养分质量分数均随侵蚀程度的加深而减少,施肥可以增加土壤中有机质及各养分的质量分数,但施肥后各养分的质量分数整体上仍呈现出随侵蚀深而降低的趋势;3）土壤侵蚀会减少玉米的生物量,平均每侵蚀1am土层,玉米生物量下降0．38％,施肥可以在一定程度上弥补侵蚀所造成的损失;4）同生物量的变化情况,玉米产量也呈现出随侵蚀程度加深而逐渐下降的趋势,每流失1cm土层,玉米产量平均下降2．49％,施肥能够提高一定的玉米产量,在剥离地表20cm、剥离地表10cm、原状未扰动土和覆盖10cm表土4种不同的地表处理下,常规施肥下的玉米产量比无肥分别提高2．44％、2．13％、1．50％和1．23％,过量施肥比无肥分别提高2．99％、2．56％、1．98％、1．14％。     

Diversified cropping systems in semiarid Montana: Nitrogen use during drought

Improved nitrogen use efficiency would be beneficial to agroecosystem sustainability in the northern Great Plains of the USA. The most common rotation in the northern Great Plains is fallow–spring wheat. Tillage during fallow periods controls weeds, which otherwise would use substantial amounts of water and available nitrogen, decreasing the efficiency of fallow. Chemical fallow and zero tillage systems improve soil water conservation, and may improve nitrogen availability to subsequent crops. We conducted a field trial from 1998 through 2003 comparing nitrogen uptake and nitrogen use efficiency of crops in nine rotations under two tillage systems, conventional and no-till. All rotations included spring wheat, two rotations included field pea, while lentil, chickpea, yellow mustard, sunflower, and safflower were present in single rotations with wheat. Growing season precipitation was below average in 3 of 4 years, resulting in substantial drought stress to crops not following fallow. In general, rotation had a greater influence on spring wheat nitrogen accumulation and use efficiency than did tillage system. Spring wheat following fallow had substantially higher N accumulation in seed and biomass, N harvest index, and superior nitrogen use efficiency than wheat following pea, lentil, chickpea, yellow mustard, or wheat. Preplant nitrate-N varied widely among years and rotations, but overall, conventional tillage resulted in 9 kg ha⁻¹ more nitrate-N (0–60 cm) for spring wheat than did zero tillage. However, zero tillage spring wheat averaged 11 kg ha⁻¹ more N in biomass than wheat in conventional tillage. Nitrogen accumulation in pea seed, 45 kg ha⁻¹, was superior to that of all alternate crops and spring wheat, 17 and 23 kg ha⁻¹, respectively. Chickpea, lentil, yellow mustard, safflower, and sunflower did not perform well and were not adapted to this region during periods of below average precipitation. During periods of drought, field pea and wheat following fallow had greater nitrogen use efficiency than recropped wheat or other pulse and oilseed crops.     

Studies on Persian clover (Trifolium resupinatum)

Yields of green fodder, dry matter and nitrogen were adversely affected by an increase in the harvesting interval of Persian clover from 40 to 100 days. The optimum harvesting interval which gave maximum yield of green fodder (86.6 ton/ha) and dry matter (11.2 ton/ha) was 30 days. The maximum yield of total nitrogen (423 kg/ha) was obtained when the harvesting interval was 20 days.     

除草杀虫药肥在水稻上的应用效果

为了探索除草杀虫药肥在水稻上的除草、杀虫和增产效果,2014年在湖南省祁东县、泪罗市和桂东县3地进行田间对比试验.结果表明,除草杀虫药肥对水稻田中的稗草、鸭舌草、矮慈姑、牛毛毡、三棱草、异型莎草等一年生杂草及稻田早期害虫如二化螟的防效较好,药后45d株防效为90.5％ ～97.9％,药后30 d二化螟防效为86.5％～98.4％;与空白对照相比,产量可增加90.0～151.6 kg/667m2,增幅达18.4％ ～21.7％,投入产出比为1∶3.2～1∶6.5,经济效益可观;并且该药肥施用操作简单方便,省工省力,值得大力推广.     

Processing potential of potato cultivars at early harvests

Summary Assessments were made in three seasons of yields and tuber dry-matter percentages at harvests from June to early August in a range of cultivars gorwn at a coastal site in south-west Wales. Lareg differences in tuber dry-matter percentage were found between cultivars within seasons and also at similar dates between seasons.The cultivar Home Guard produced consistently high dry-matter percentages each year in the period from late June to early August but cv. Redord achieved similar or higher dry-matter contents after mid-Julyl. Most other cultivars produced lower dry matter percentages throughout the sampling period. The potential for the use of early maturing cultivars in late June and July for processing into crisps is discussed.     

长期定位施肥对小麦籽粒产量及品质的影响

为了探讨长期施肥对冬小麦籽粒产量及品质的影响，以12年长期定位试验为基础，对冬小麦籽粒产量变化及加工品质进行了研究。结果表明：(1)缺氮或缺磷处理(CK、N、NK、PK)小麦产量低而不稳，年均产量1059～1291kg／hm^2，变异系数40．46％～62．11％；氮磷、氮磷钾配施或氮磷钾与有机物配施(NP、NPK、SNPK、M(N)NPK、M(H)NPK)能持续高产，年均产量5237～5646kg／hm^2，变异系数为23．11％～34．23％。(2)CK、N、NK处理籽粒的蛋白质含量、湿面筋含量、干面筋含量、沉淀值均高于NP、NPK、SNPK、M(N)NPK、M(H)NPK处理，说明小麦优质和高产所要求的养分平衡点不同。(3)要兼顾冬小麦产量和品质，须平衡施肥，重视氮、磷肥的投入。     

仪征市30年耕地养分时空变化趋势及其与粮食生产的关系

通过对仪征近30年来地力调查与定位监测数值、粮食产量数据、气象数据、肥情调查数据的分析,得出下列结果:30年间有机质变化呈显先降后升的趋势,这和农田有机物质的投入与消耗的数量平衡有关;速效P呈显先升后降再上升的趋势,速效K呈显逐渐上升的趋势,这和P、K化肥用量变化有关;有效Zn呈上升趋势,有效B呈下降趋势,这和种植业结构调整关系密切。30年间粮食生产出现先升后降再上升的趋势,粮食产量的变化受多种因素综合影响,育种技术突破引发产量大幅度提高,气候因素影响当季产量的变化,而耕地养分质量指数(SNQI)的时空变化与粮食产量的变化关系最为密切,且SNQI值越高粮食产量年度间变幅越小,抗风险能力越强。     

爱丰有机腐殖酸液肥在小麦上的试验效果研究

爱丰有机腐殖酸液肥是采用德国先进的酶促矿化剂为核心成分,配以腐殖酸、草碳、氮、磷、钾、钙、镁、硫及铜、锰、硼、钼等多种微量元素精制而成的一种无毒、无污染的高活性绿色有机液体肥料。它可以提高作物产量,改善农作物品质,增强抗逆能力。为进一步了解爱丰有机肥对小麦生长发育的影响,我们在不同时期对小麦进行叶面喷施,研究其在小麦上的应用效果和合理使用方法,更好地发挥其在生产中的作用。     

菜青虫为害春甘蓝不同生育期对产量的影响及经济阈值的研究

应用均匀设计方法,测定了菜青虫连续为害春甘蓝结球始期和菜球充实期造成的产量损失,并应用生命表方法评价了春甘蓝上有青虫天敌的作用,建立了包括甘蓝生育期和菜青虫种群密度在内的产量损失模型和包含各类天敌作用的防治指标模型。结果表明,产量损失主要是由甘蓝结球始期的虫害造成,捕食性天敌对菜青虫控制作用最大,其排除作用控制指数为4．7107。根据防治指标模型,可求出甘蓝结球始期和菜球充实期以1－2龄幼虫、3－4龄幼虫、5龄幼虫为依据的防治指标,分别为每株14．13头、7．69头、3．44头（结球始期）,29．34头、12．26头和6．93头（菜球充实期）。