Pig Compost Use on Zinc and Copper Concentrations in Soils and Corn Plants

The use of pig compost (PC) in agricultural land has increased in Chile in the last years. This organic amendment is a valuable nutritional source for crops, but its applying must be done in a controlled manner since it exhibited high copper (Cu) and zinc (Zn) concentrations. A short-term field experiment was conducted out to study the effects of increasing PC rates on the production and quality corn crop in two soils located at south central Chile. Five treatments were evaluated: control without fertilization (C), conventional fertilization (CF) (350 kg N ha-1), and three increasing PC rates (15.33, 30.65, and 61.31 Mg&middotha-1, corresponding to 350, 700, and 1400 kg N ha-1, respectively) in a split plot design with four replicates. The overall results indicated that dry matter production, grain yield, and plant Zn and Cu concentrations were similar among fertilization sources and rates. Extractable soil Zn concentration exhibited a rate-related increase of PC in both locations, while Cu concentration exhibited this behavior only at the soil located in Chillan. Nevertheless, the values obtained were below of those considered phytotoxic levels. Therefore, the contribution of Zn and Cu through PC applying at different rates to the soils studied showed a slight affect in soil extractable Zn and Cu values without negatively effects on quantity and quality corn crop. The organic amendment applied can be a good and cheaper substitute to conventional fertilization, although further monitoring of Zn and Cu soil levels should be carried out to avoid any environmental risk.

Phosphate Biofertilizer, Row Spacing and Plant Density Effects on Corn (<i>Zea mays</i>L.) Yield and Weed Growth

A field study was conducted at the Agricultural Research Farm of Razi University, Kermanshah, Iran to investigate the effects of phosphate biofertilizer, row spacing and plant density on corn yield and weed growth. The experiment was a factorial with three factors arranged in a randomized complete block design with three replications. The first factor was phosphate biofertilizer (inoculation and non-inoculation), the second was row spacing (conventional (75 cm) and reduced (50 cm)) and the third was plant density (66,666 plants·ha–1 (conventional plant density) 83,333 and 99,999 plants·ha–1 (1.25 and 1.5 times the conventional plant density, respectively)). Results indicated that corn yield and weed growth were significantly influenced by row spacing and plant density. So that, corn yield improved and weed biomass diminished in response to increasing plant density and decreasing row spacing. However, phosphate biofertilizer had no significant effect on corn yield, whereas, weed biomass was notably increased when phosphate biofertilizer was applied. Overall, this study revealed that both yield and weed control in corn field can be improved by alteration of the planting arrangement.

Effects of Plant Density on Forage Nutritive Value of Whole Plant Corn

In the field experiment, the effects of plant densities (75 000, 112 500 and 150 000 plants ha-1) on forage nutritive value of whole plant corn (WPC) were studied from 1999 to 2001. The results demonstrated that with the increasing of plant density, the forage matter yield per plant corn decreased significantly, while the fresh matter and dry matter per hectare corn increased significantly, and a higher grains yield was gotten at higher plant densities. Forage nutritive quality of whole plant corn was changed as plant density increased, the crude protein (CP), ether extract (EE), crude fiber (CF), nitrogen free extract (NFE) and general energy (GE) yields increased obviously. Increas- ing plant density reasonably with the application of plant growth regulators could improve plant properties, harvest more forage matter, and enhance forage nutritive value of WPC.

Effect of Plant Growth-Promoting Rhizobacteria at Various Nitrogen Rates on Corn Growth

Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture, an increasing number of researchers are investigating ways to improve the efficiency of PGPR use to reduce chemical fertilizer inputs needed for crop production. Accordingly, greenhouse studies were conducted to evaluate the impact of PGPR inoculants on biomass production and nitrogen (N) content of corn (Zea mays L.) under different N levels. Treatments included three PGPR inoculants (two mixtures of PGPR strains and one control without PGPR) and five N application levels (0%, 25%, 50%, 75%, and 100% of the recommended N rate of 135 kg N ha&#8722;1). Results showed that inoculation of PGPR significantly increased plant height, stem diameter, leaf area, and root morphology of corn compared to no PGPR application under the same N levels at the V6 growth stage, but few differences were observed at the V4 stage. PGPR with 50% of the full N rate produced corn biomass and N concentrations equivalent to or greater than that of the full N rate without inoculants at the VT stage. In conclusion, mixtures of PGPR can potentially reduce inorganic N fertilization without affecting corn plant growth parameters. Future research is needed under field conditions to determine if these PGPR inoculants can be integrated as a bio-fertilizer in crop production nutrient management strategies.

Relationship of late-season ear leaf nitrogen with early- to mid-season plant height of corn

Nitrogen concentration in the ear leaf is a good indicator of corn (Zea mays L.) N nutrition status during late growing season. This study was done to examine the relationship of late-season ear leaf N concentration with early- to mid- season plant height of corn at Milan, TN from 2008 to 2010 using linear, quadratic, square root, logarithmic, and exponential models. Six N rate treatments (0, 62, 123, 185, 247, and 308 kg·N·ha-1) repeated four times were implemented each year in a randomized complete block design under four major cropping systems: corn after corn, corn after soybean [Glycine max (L.) Merr.], corn after cotton [Gossypium hirsutum (L.)], and irrigated corn after soybean. The relationship of ear leaf N concentration determined at the blister growth stage (R2) with plant height measured at the 6-leaf (V6), 10-leaf (V10), and 12-leaf (V12) growth stages was statistically significant and positive in non-irrigated corn under normal weather conditions. However, the strength of this relationship was weak to moderate with the determination coefficient (R2) values ranging from 0.21 to 0.51. This relationship was generally improved as the growing season progressed from V6 to V12. Irrigation and abnormal weather seemed to have adverse effects on this relationship. The five regression models performed similarly in the evaluation of this relationship regardless of growth stage, year, and cropping system. Our results suggest that unlike the relationship of corn yield at harvest with plant height measured during early- to mid-season or the relationship of leaf N concentration with plant height when both are measured simultaneously during early- to mid-season, the relationship of late-season ear leaf N concentration with early- to mid-season plant height may not be strong enough to be used to develop algorithms for variable-rate N applications on corn within a field no matter which regression model is used to describe this relationship.

全株玉米青贮饲料的制作及在肉牛养殖中的应用

全株玉米青贮饲料在养殖中的应用范围越来越广,但在实际操作中仍然存在不少问题。本文总结了全株玉米的制作方法及在肉牛养殖中的应用,旨为广大收贮企业规范制作全株玉米青贮饲料及肉牛养殖场户科学饲喂提供参考。

基于混合分组扩张卷积的玉米植株图像深度估计

【目的】研究面向玉米田间场景的图像深度估计方法,解决深度估计模型因缺少有效光度损失度量而易产生的精度不足问题,为田间智能农业机械视觉系统设计及导航避障等提供技术支持。【方法】应用双目相机作为视觉传感器,提出一种基于混合分组扩张卷积的无监督场景深度估计模型。设计一种混合分组扩张卷积结构及对应的自注意力机制,由此构建反向残差模块和深度估计骨干网络;并将光照不敏感的图像梯度和Gabor纹理特征引入视图表观差异度量,构建模型优化目标。以田间玉米植株图像深度估计为例,开展模型的训练和测试试验。【结果】与固定扩张因子相比,采用混合分组扩张卷积使田间玉米植株深度估计平均相对误差降低了63.9%,平均绝对误差和均方根误差则分别降低32.3%和10.2%,模型精度显著提高;图像梯度、Gabor纹理特征和自注意力机制的引入,使田间玉米植株深度估计平均绝对误差和均方根误差进一步降低3.2%和4.6%。增加浅层编码器的网络宽度和深度可显著提高模型深度估计精度,但该处理对深层编码器的作用不明显。该研究设计的自注意力机制对编码器浅层反向残差模块中不同扩张因子的卷积分组体现出选择性,说明该机制具有自主调节感受野的能力。与Monodepth2相比,该研究模型田间玉米植株深度估计的平均相对误差降低48.2%,平均绝对误差降低17.1%;在20 m采样范围内,估计深度的平均绝对误差小于16 cm,计算速度为14.3帧/s。【结论】基于混合分组扩张卷积的图像深度估计模型优于现有方法,有效提升了深度估计的精度,能够满足田间玉米植株图像的深度估计要求。

大豆玉米带状种植模式下玉米摘穗机设计与试验

针对丘陵山区大豆玉米带状种植模式的玉米果穗收获有机难用、无机可用的现状,设计一款自走式小型玉米摘穗机。该机采用纵卧式摘穗辊实现果穗摘取,并通过输送装置收集装袋;采用“Y”型布局的L型小甩刀实现茎秆粉碎。对摘穗过程进行动力学分析、对粉碎过程进行静力学分析,确定其核心装置设计参数并进行样机试制。以茎秆粉碎长度合格率、果穗损失率、籽粒破碎率为试验指标进行田间试验,来验证该机设计的合理性。试验表明:在生产率为0.8 hm^(2)/d、果穗籽粒含水率为26.38%、茎秆含水量为71.25%的条件下进行试验,茎秆粉碎长度合格率为92.4%、果穗损失率为2.06%、籽粒破碎率为0.61%。该机设计各项指标符合国家相关标准,能够满足丘陵山地地区玉米机械化收获需求。

全株玉米青贮有氧稳定性对延缓全混合日粮夏季发热的影响

本文通过研究不同有氧稳定性的全株玉米青贮对全混合日粮(TMR)在夏季发热的影响,以期探索防止TMR发热的新途径。本研究选择制作工艺和营养水平相似的3个青贮窖进行全株玉米青贮及其TMR有氧稳定性测定。制作全株玉米青贮时,青贮窖A喷洒了乳酸菌发酵剂2,青贮窖B喷洒乳酸菌发酵剂1和有机酸盐保鲜剂,青贮窖C中全株玉米青贮喷洒了乳酸菌发酵剂1。同时测定,3种全株玉米青贮及其TMR的有氧稳定性。结果表明,青贮窖A、青贮窖B和青贮窖C的全株玉米青贮有氧稳定性分别为36 h、>85.8 h和>79.5 h。相对应的全株玉米青贮制作出的TMR有氧稳定性分别为9.5、31.5和29.5 h。由此可见,有氧稳定性好的全株玉米青贮可以延缓奶牛TMR的二次发酵,提高其有氧稳定性。

勉县玉米-大豆带状复合种植玉米品种筛选试验

玉米-大豆带状复合种植技术目标是保证带状复合种植条件下玉米与单作相比不减产,增收一季豆。与玉米常规种植相比,种植的株行距变化较大,密度增加,玉米品种的株型、耐密性、抗逆性、丰产性等指标成为此项技术应用成功的前提。通过试验,“1.8m带型2+2模式”玉米-大豆带状复合种植玉米品种主推登海605、农科大8号和延科288,搭配种植五单2号、中金368。

玉米“适应性负效应”现象探讨——西南喀斯特石漠化成因新解

南方的石漠化,北方的沙漠化,是困扰中国的两大生态环境问题。为探寻西南喀斯特石漠化的形成原因,利用文献法、参与式田野调查法以及经验实证法,梳理了近四十年来西南喀斯特石漠化形成的各种成因说,并以贵州为例,详细论述了石漠化形成的三个阶段,以及石漠化与玉米的关系。在此基础上揭示了玉米在石漠化地区存在“适应性负效应”,合理地解释了西南喀斯特石漠化形成原因。此观点的提出,可为西南喀斯特石漠化形成原因做出新的阐释,同时也可为西南石漠化治理提供理论支持与科学依据。

玉米大豆带状复合种植模式研究

为探讨适宜云南玉米大豆带状复合种植模式,2022年选用玉米云瑞668和大豆台湾75-3为试验材料进行大田试验,研究玉米大豆带状复合种植不同模式下不同处理对玉米和大豆农艺性状和产量构成因素的影响。结果表明,可机械化作业的田块应优先选用玉米大豆行比4∶4和4∶3模式,山区或半山区推广玉米大豆行比2∶2模式。该研究为玉米、大豆带状复合种植在云南省保山市及气候类似地区推广提供了理论依据。

Nutrient Content in Soils and Adaptability of Corn in Yuanzhou District,Guyuan City

[Objective] The aim was to research rational fertilization of corn in Yuanzhou District, Guyuan, Ningxia Hui Autonomous Region. [Method] Nutrient con- tents in soils in Yuanzhou District were measured with conventional analysis method and the suitable fertilization scheme of corn growth was proposed based on fertiliz- er-application rule of corn growth and nutrient balance. [Result] Soil in farmlands in Yuanzhou District was of alkalinity; organic matter, N, P and Zn were shortage; S was extremely insufficient; Fe and Mn were moderate; K was abundant; Cu would satisfy crop growth, [Conclusion] The research provides references for yield increase, reduction of chemical fertilizer and related pollution for corn growth.

一型手推式玉米小区播种机研制与试验

由于我国育种单位众多且较分散,考虑投入产出比等经济效益指标影响,面临着小区试验面积小、分布不均等问题。针对玉米小区试验播种用工多、出苗差等问题,研制一种简单实用的手推式玉米小区试验播种机。对比国内外研发推广的小区播种机,该机械对操作人员技术要求不高,操作更简单;对播种地块、种子排列没有严格要求,实用性更强。非常切合我国玉米育种现状,具有很好的应用前景。

通辽地区种植密度和添加剂对4个品种全株玉米青贮后发酵品质、营养成分和体外消化率的影响

本试验旨在研究品种、种植密度和添加剂对通辽地区全株玉米青贮发酵品质、营养成分和体外消化率的影响。以“大康205”、“高油958”、“中玉335”和“中农787”共4个品种的全株玉米为材料,设置6.75×104和8.25×10^(4)株/hm^(2)共2个种植密度,收获后添加布氏乳杆菌(Lentilactobacillus buchneri),制作全株玉米青贮,室温下发酵200 d后通过测定其发酵品质、常规营养成分以及体外消化率,并运用相关性分析的方法,进行青贮品质的综合评价。结果表明:1)4个品种的全株玉米青贮后pH都在4.0以下;“高油958”青贮的乙酸(AA)含量显著高于“大康205”青贮(P<0.05),氨态氮(NH3⁃N)含量显著低于其他品种(P<0.05)。8.25×10^(4)株/hm^(2)种植密度全株玉米青贮发酵品质优于6.75×10^(4)株/hm^(2)种植密度。添加布氏乳杆菌的全株玉米青贮乳酸(LA)和AA含量高于无添加剂(P>0.05)。2)“大康205”青贮的干物质(“高油958”除外)和淀粉含量著高于其他品种(P<0.05),中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量最低,显著低于“中玉335”青贮(P<0.05);“高油958”青贮的营养品质次于“大康205”青贮。8.25×10^(4)株/hm^(2)种植密度全株玉米青贮营养品质优于6.75×10^(4)株/hm^(2)种植密度。添加布氏乳杆菌后青贮营养品质得到提升。3)“高油958”青贮的体外干物质消化率(IVDMD)最高,显著高于“大康205”和“中玉335”青贮(P<0.05)。4)全株玉米青贮NDF和ADF含量与LA和AA含量呈显著正相关(P<0.05),NH3⁃N含量与pH和IVDMD呈显著负相关(P<0.05)。综上可知,“大康205”和“高油958”品种玉米的青贮品质较好,高种植密度(8.25×10^(4)株/hm^(2))的全株玉米青贮营养成分更高,添加布氏乳杆菌可提高全株玉米青贮发酵品质;综合评价得出,“高油958”适宜在通辽地区作为青贮玉米推广种植。

指夹式亚高速玉米播种不同导种管种子运移轨迹对比

为了解决玉米亚高速播种机作业速度为8~12km/h条件下,指夹排种器导种管选型问题,以14°和16°两种角度的导种管为研究对象,通过自制试验台架并利用高速摄像技术对玉米种子在不同导种管中的运动过程进行追踪拍摄,描述了指夹排种器分别在作业速度8~12km/h、倾斜角度0°~30°、离地高度2~4cm 3种因素下,种子落入不同导种管的位移轨迹,结果表明:种子在16°导种管比在14°导种管中弹跳剧烈。

热带作物秸秆覆盖对土壤质量及玉米产量和品质的影响

【目的】探究甘蔗叶、菠萝茎叶等热带作物秸秆作为农业覆盖材料对土壤质量及玉米生长的影响,为热带作物秸秆废弃物资源化利用提供参考依据。【方法】以玉米为种植对象,采用田间小区对比试验,设置甘蔗叶覆盖(SLM)、腐熟甘蔗叶覆盖(RSLM)、菠萝茎叶覆盖(PLM)和富贵竹茎叶覆盖(FLM)4个处理,以塑料地膜覆盖(CK1)和无覆盖(CK2)为对照,研究不同秸秆覆盖对土壤pH、有机质、全氮、有效磷和速效钾的影响,以及对玉米产量和品质的影响。【结果】热带作物秸秆覆盖,与无覆盖相比,可以有效提升土壤pH、有机质、全氮、有效磷和速效钾含量,对提升土壤质量具有积极作用。富贵竹茎叶覆盖效果最显著,与塑料地膜覆盖相比,土壤pH提高9.01%,有机质提高6.42%,全氮提高17.59%,速效钾提高477.79%,有效磷含量低于塑料地膜覆盖,但差异不显著;与无覆盖相比,土壤pH提高22.22%,有机质提高21.63%,全氮提高24.51%,有效磷提高2.74%,速效钾提高389.38%。腐熟甘蔗叶和富贵竹茎叶覆盖可以显著提升玉米产量,其他秸秆覆盖对玉米产量和品质的影响均不显著。【结论】热带作物秸秆覆盖可以提升土壤质量、促进玉米增产,富贵竹茎叶覆盖在改良土壤方面的效果显著,腐熟甘蔗叶覆盖对于玉米增产有较好的促进作用。

棉花秸秆分别与全株玉米、甜菜渣混合青贮的营养价值研究

试验旨在探究棉花秸秆分别与全株玉米、甜菜渣混合青贮的营养特性及饲用价值。试验分为3组,对照组(CK组)使用全株玉米青贮,A组、B组棉花秸秆分别与全株玉米、甜菜渣按1∶1混合青贮,每组3个重复,发酵90 d后取样,分析青贮饲料的发酵品质、营养特性及饲用价值等指标。结果显示,与CK组相比,A组和B组青贮饲料的pH值升高(P<0.05),费氏评分降低(P<0.05);A组和B组的粗蛋白(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量升高(P<0.05),非纤维性碳水化合物(NFC)含量降低(P<0.05)。A组饲料相对饲喂价值(RFV)和粗饲料相对质量(RFQ)高于B组(P<0.05)。与CK组相比,A组和B组的体外产气量降低,其中A组的体外产气量高于B组。A组和B组的干物质降解率(IVDMD)低于CK组(P<0.05)。研究表明,棉花秸秆分别与全株玉米、甜菜渣混合青贮饲料的饲用价值仍低于全株玉米青贮饲料,但A组与CK组的饲用价值较接近,应用潜力较高。

不同种类添加剂对全株玉米发酵特性及营养品质的影响

试验旨在筛选适用于全株玉米青贮调制的添加剂种类及添加量,促进青贮玉米产业化开发。以蜡熟期全株玉米为原料,研究甲酸、乳酸菌和糖蜜对全株玉米发酵特性、营养品质及有氧稳定性的影响。结果显示:与自然发酵相比,6 mL/kg甲酸可显著降低青贮饲料中不良微生物的数量及氨态氮(NH_(3)-N)含量(P<0.05),提高了可溶性碳水化合物(WSC)含量及有氧稳定性。添加布什乳杆菌或植物乳杆菌+布什乳杆菌复合菌剂可显著增加乙酸含量(P<0.05),降低不良微生物数量及NH_(3)-N含量,提高有氧稳定性。添加糖蜜显著增加了青贮饲料中有害菌的数量及NH_(3)-N含量(P<0.05),降低了乙酸、干物质(DM)和WSC含量。研究表明,综合考虑全株玉米青贮饲料的发酵特性、营养品质及有氧稳定性,生产中推荐采用6 mL/kg甲酸、单独添加布氏乳杆菌或按1∶5配比添加植物乳杆菌与布氏乳杆菌复合菌剂对全株玉米进行青贮。

大豆—玉米带状复合种植耕种机械化研究进展

为充分发挥大豆—玉米带状复合立体化种植技术优势,保证我国粮油安全,解决作物争地矛盾,配套的复合耕种机械化研究成为首要环节。从国内典型多种植模式出发,总结地区间套作技术下大豆—玉米配套耕种机械特点,围绕耕种机具整地、洁茬、施肥、排种、播深及投种等作业阶段,阐述对比耕种机械技术工作原理,发现实际生产中仍存在秸秆拥堵、种肥排量和位置不协同、播深变异系数大和投种着床不均匀等问题,从农机农艺融合方面提出轻扰低耗洁茬、处方分层施肥、种肥电驱变量控制、多传感智能仿形播种、种粒平稳着床等一系列改良大豆—玉米复合耕种机械的路径,以期促进绿色高效发展。