配合施肥对云南冬季亚麻生长及土壤肥力的影响

如何保证亚麻正常生长和亚麻地土壤肥力稳定及养分平衡，是亚麻新产区非常关注的问题。以氮、磷、钾和几种主要微量元素进行2因素随机区组试验的结果显示．不同肥料处理组合对亚麻农艺性状的影响各不相同，对有效株数影响最大．单茎重、株高与工艺长度居其次，而茎粗所受影响最小，且大量元素对亚麻生长的影响要比微量元素更大。依据亚麻综合性状表现，配合施肥以A381、A2BO、A382、A282处理组合比较理想，亚麻原茎产量达到13．3t／hm^2以上。在配合适量施肥前提下．亚麻地土壤肥力基本保持稳定。     

Influence of Pre-Plant Micronutrient Mixes and Ammonium to Nitrate Ratios in Fertilizer Solution on Growth and Micronutrient Contents of Marigold in Plug Culture

ABSTRACT

The purpose of this work was to determine the effects of pre-plant micronutrient mixes and various ammonium/nitrate (NH₄ ⁺/NO₃ ^?) ratios in a fertilizer solution on growth and the nutrient uptake of French marigold ‘Orange Boy’ in a plug culture. Two kinds of granular glass frits containing six micronutrients were produced and incorporated into peatmoss+vermiculite (1:1, v/v) substrate at a rate of 0.3 g · L^{? 1}. The five NH₄ ⁺/NO₃ ^? ratios in fertilizer solution were 0/100, 25/75, 50/50, 75/25, and 100/0, each giving a total nitrogen (N) supply of 80, 100, and 120 mg · L^{? 1}in the root substrate during stages 2, 3, and 4, respectively. The plants produced a significantly higher fresh and dry matter yield at 35 days after sowing when grown in 25/75 N nutrition in micronutrient fertilizer 1 (MF1) and 50/50 in micronutrient fertilizer 2 (MF2) than in the other NH₄ ⁺/NO₃ ^? ratios tested. Treatments of the highest accumulation of iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), and boron (B) in plants were 25/75, 50/50, 50/50, 25/75 and 50/50 in MF1 and 50/50, 25/75, 50/50, 50/50, 50/50 in MF2, respectively. The trends in accumulations of Fe, Mn, Zn, Cu, and B in plants were quadratic (Q), linear (L) and Q, L and Q, L and Q, and Q, respectively, in MF1. Those in MF2 were Q, Q, Q, L and Q, and Q, respectively.     

Enhanced nutrient and rainwater use efficiency in maize and soybean with secondary and micronutrient amendments in the rainfed semi-arid tropics

In view of widespread deficiencies, a long-term experiment was started at the International Crops Research Institute for the Semi-Arid Tropics, Patancheru, India in 2007 to identify economically efficient application strategy (full or 50% dose every or every second year) of sulphur (S) (30 kg ha^?1), boron (B) (0.5 kg ha^?1) and zinc (Zn) (10 kg ha^?1). During the fourth year in 2010, balanced fertilization through adding S, B and Zn increased maize grain yield by 13–52% and soybean yield by 16–28% compared to nitrogen (N) and phosphorus (P) fertilization alone. Balanced nutrition increased N and P uptake, utilization and use efficiency for grain yield and harvest index indicating improved grain nutritional quality. The N, P plus 50% of S, B and Zn application every year recorded highest crop yields and N and P efficiencies indices and increased rainwater use efficiency with a benefit:cost ratio of 11.9 for maize and 4.14 for soybean. This study showed the importance of a deficient secondary nutrient S and micronutrients B, Zn in improving N and P use efficiency while enhancing economic food production.     

Improving agricultural water use efficiency by nutrient management in crop plants

Abstract

Improvement of agricultural water use efficiency is of major concern with drought problems being one of the most important factors limiting grain production worldwide. Effective management of water for crop production in water-scarce areas requires efficient approaches. Increasing crop water use efficiency and drought tolerance by genetic improvement and physiological regulation may be a means to achieve efficient and effective use of water. A limited water supply inhibits the photosynthesis of plants, causes changes of chlorophyll contents and components and damage to photosynthetic apparatus. It also inhibits photochemical activities and decreases the activities of enzymes in plants. Water stress is one of the important factors inhibiting the growth and photosynthetic abilities of plants through disturbing the balance between the production of reactive oxygen species and the antioxidant defence, causing accumulation of reactive oxygen species which induce oxidative stress to proteins, membrane lipids and other cellular components. A number of approaches are being used to enhance water use efficiency and to minimize the detrimental effect of water stress in crop plants. Proper plant nutrition is a good strategy to enhance water use efficiency and productivity in crop plants. Plant nutrients play a very important role in enhancing water use efficiency under limited water supply. In this paper we discuss the possible effective techniques to improve water use efficiency and some macronutrients (nitrogen, phosphorus, potassium, calcium and magnesium), micronutrients (zinc, boron, iron, manganese, molybdenum and chloride), and silicon (a beneficial nutrient) in detail to show how these nutrients play their role in enhancing water use efficiency in crop plant.     

Low manganese (Mn) and copper (Cu) concentrations in cereals explained yield losses after lime application to soil

Abstract

A range of locally available liming materials of different geological origin, particle size, and application rate were investigated in 15 field sites over a period of 8 years. At 5 sites, lime addition to soils caused average yield losses of 7%. Concentrations of Mn and Cu but not of boron and zinc in grains declined in limed plots. Decline in concentrations of Mn and Cu were significantly correlated with increasing soil pH-values. Crop data indicated that concentrations of Mn and Cu in grains reached low, critical levels. Yields declined at threshold values amounting to 15 mg Mn kg^?1 for wheat and barley, 25 mg Mn kg^?1 for rye, 30 mg Mn kg^?1 for oat, and 3 mg Cu kg^?1 for the four cereals.     

Season-Dependent Fruit Loading: Effect on Nutrient Homeostasis of Tomato Plants

ABSTRACT

Greenhouse tomato plants were grown hydroponically during the period of lower temperatures of winter (LT) versus the period of higher temperatures of summer (HT). In these plants, the effect of season on fruit load was dramatic. In order to study the alterations season introduces to the developmental allocation of nutrients within the various organs, concentrations of total nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were determined during each season at weekly intervals in the dry mass of leaves and roots and in the extract of upper, middle, and lower parts of the stem. The level of N/P ratio was always higher in the leaves than in the roots, and these differences were more intense during HT. The short-term changes of ratio in the leaves during HT and LT were positively related with the changes in temperature (r = 0.59 and 0.51 for HT and LT, respectively). In contrast, such correlations in the root were negative (r = ?0.54 and r = ?0.33 for HT and LT, respectively). The increase of temperature increased P uptake but not its translocation to upper plant parts. HT affected the translocation of N, K, Mg, and Ca more and their uptake less. Fruit load differentially affected the concentration of nutrients. In contrast to total N and K, Ca concentration in plant parts presented a positive relation with the increase of fruit load. Calcium and total N concentration (as opposed to P and micronutrient concentrations) were always higher in the leaves than in the roots. Under HT conditions, P was accumulated in roots in combination with high concentrations of Fe, Zn, and Mn. On the other hand, K and N were accumulated in the roots during the period of low temperature in winter. Calcium and K compared with other nutrients presented a pronounced tendency to be transported toward the top of the stem during HT, and their extractable concentration in the upper part of stem presented a significant increase during summer. Extractable K concentration was two to nine times higher than that of the other macronutrients. Our data suggest that the extractable concentration of nutrients of the stem is a good index for the diagnosis of the mineral nutritional status of the plant.     

Effects of Lead,EDTA, and IAA on Nutrient Uptake by Alfalfa Plants

ABSTRACT

The element concentrations of alfalfa plants exposed for 10 d to 40 mg lead (Pb) L^{? 1} from lead nitrate [Pb(NO₃)₂] alone, or combined with ethylenediaminetetraacetic acid (EDTA) and indole-3-acetic acid (IAA), was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Indole-3-acetic acid at 10 μ M and Pb/EDTA/IAA at 10 μ M increased potassium (K) concentration in roots by 87% and 94%, respectively (P < 0.05). However, IAA at 100 μ M decreased K concentration in leaves (P < 0.05). Plants exposed to 100 μ M IAA, Pb/IAA at 100 μ M, and Pb/EDTA/IAA at 100 μ M had, respectively, 30%, 55%, and 40% more sulfur (S) in leaves than control plants (P < 0.05). Lead and Pb/IAA reduced Ca concentration in stems and leaves (P < 0.05). Conversely, Pb and Pb/EDTA increased Cu concentration in roots and stems. IAA at 100 μ M, Pb, and Pb/EDTA/IAA decreased Zn concentration in roots (P < 0.05). Manganese (Mn) and molybdenum (Mo) concentration in roots and stems was lower in plants treated with Pb and Pb/IAA (P < 0.05). Pb and Pb/IAA reduced (P < 0.05) the iron (Fe) concentration in roots. However, the addition of EDTA and IAA at 10 μ M reduced the negative effects of Pb on Fe absorption.     

Effects and rates of broiler and layer manures on the leaf yield and tissue nutrient contents of moringa (Moringa oleifera Lam.) in Swaziland

Abstract

Moringa (Moringa oleifera Lam) has been gaining increasing attention in Swaziland as a medicinal plant increasingly being exploited due to its medicinal value especially amongst people living with HIV/AIDS. The tree is being cultivated in most homesteads and fertilized using poultry manure. A pot experiment was conducted in the greenhouse during the 2016/2017 cropping season. The aim was to investigate the effects two sources of manure (i.e. broiler and layer) at five rates (0, 15, 30, 45 and 60 tonnes/ha) on dry matter yield (i.e. leaves, petioles, stems and roots) and tissue nutrient contents of moringa. The experimental design was a randomized complete block design (RCBD) in a factorial arrangement with four replicates. Data collected (i.e. number of leaves/plant, dry matter of leaflets, stems, roots and tissue nutrients- Fe, Mn, Zn, Cu and Cd) were analyzed using Statistical Analysis Software. Results showed that the application of broiler and layer manures at different rates had no significant effect (p?>?0.05) on the number of leaves/plant. The dry matter yields were significantly different considering the sources and rates of manure applications. Furthermore, results showed that the tissue nutrient contents of micronutrients (i.e. Fe, Mn, Zn and Cu) and Cd were generally higher than the maximum permissible limits (MPL) of the World Health Organization as well as daily dietary intake for medicinal plants. Evidence from this study suggest that moringa can successfully be grown using poultry manures however, the application of the aforementioned manures was found to result in elevated contents of micronutrients and cadmium in plant tissue which may be harmful for human consumption.     

Alleviation of drought stress in winter wheat by late foliar application of zinc,boron, and manganese

In many regions, drought during flowering and grain‐filling inhibits micronutrient acquisition by roots resulting in yield losses and low micronutrient concentrations in cereal grains. A field and a greenhouse experiment were conducted to study the effect of foliar applications of zinc (Zn), boron (B), and manganese (Mn) at late growth stages of winter wheat (Triticum aestivum L.) grown with or without drought stress from booting to maturity. Foliar applications of Zn, B, and Mn did not affect grain yield in the absence of drought. However, under drought, foliar application of Zn and B in the field increased grain yield (15% and 19%, respectively) as well as raising grain Zn and B concentration, while Zn and Mn sprays in the greenhouse increased grain yield (13% and 10%, respectively), and also increased grain Zn and Mn concentrations. Furthermore, under drought stress both in the field and greenhouse experiment the rate of photosynthesis, pollen viability, number of fertile spikes, number of grains per spike, and particularly water‐use efficiency (WUE) were increased by late foliar application of micronutrients. These results indicate that by increasing WUE foliar application of Zn, B, and Mn at booting to anthesis can reduce the harmful effects of drought stress that often occur during the late stages of winter wheat production. These findings therefore are of high relevance for farmers' practice, the extension service, and fertilizer industry.