Masaru Urayama

Productivity of high-yielding crops: II Comparison of N, P, K, Ca, and Mg accumulation and distribution among high-yielding crops

By using good varieties (lines) and by applying coating urea which releases nitrogen slowly, extremely high yields were obtained in several crops. Based on the high yields and appropriate fertilizer application, it was difficult to consider in this experiment that deficiency or excess of nutrient elements (minerals) occurred in plant, so that the mineral status of crops could be adopted as criterion for high yield. The results obtained were as follows. 1. Amount of minerals absorbed was calculated by the following equation: Ym=Ym/Yb×Yb=MRI×Yb, where Yb is the biological yield, Ym is the mineral yield (amount of minerals absorbed), MRI is the mineral requirement index. The MRI did not show any significant difference between the“high yield” and “standard yield” treatments in each crop with a few exceptions, indicating that the Yb is the main factor which determines the Ym in each crop. 2. The MEI differed clearly among crops in the “high yield” treatment. MRI(N) was higher in soybean and winter whe...

Nutritional characteristics of the leaves of native plants growing in adverse soils of humid tropical lowlands.

Acid sulfate, peat, sandy podzolic, and saline soils are widely distributed inthe lowlands of Thailand and Malaysia. The nutrient concentrations in theleaves of plants grown in these type of soils were studied with the aim ofdeveloping a nutritional strategy for adapting to such problem soils. In sagoand oil palms that were well-adapted to peat soil, the N, P, and Kconcentrations were the same in the mature leaves, while the Ca, Mg, Na,and Fe concentrations were higher in the mature leaves of the oil palm thanof the sago palm. Melastoma malabathricum and Melaleuca cajuputi plantsthat were well-adapted to low pH soils, peat, and acid sulfate soils were alsostudied. It was observed that a high amount of Al accumulated in the M.marabathricum leaves, while Al did not accumulate in M. cajuputi leaves.M. cajuputi plants accumulated large amounts of Na in their leaves or stemsregardless of the exchangeable Na concentration in the soil, while M.malabathricum that was growing in saline-affected soils excluded Na.Positive relationships between macronutrients were recognized between Pand N, between K and N, and between P and K. Al showed antagonisticrelationships with P, K, Ca, Mg, Fe, Zn, Cu, and Na. Na also showedantagonistic relationships with P, K, Zn, Mn, Cu, and Al. Fe showed weakantagonistic relationships with Zn, Mn, Cu, and Al.

Productivity of High-Yielding Crops V. Root Growth and Specific Absorption Rate of Nitrogen

“Standard yield variety” and “high-yielding variety” of rice, winter wheat, maize, soybean, potato, beet, and sunflower were grown, and the relationship between root growth and absorption of nitrogen was studied. To estimate the role of root in nitrogen absorption, nitrogen absorption rate (ΔN, g N m−2 d−1) was parameterized into root dry weight (RW, g m−2) and specific absorption rate of nitrogen per root dry weight (SARN, ΔN RW−1). 1. Since during the vegetative growth stage, the correlation between ΔN and crop growth rate (CGR) was high, ΔN was under the control of shoot demand for nitrogen, while during the early maturing stage, ΔN was well correlated with SARN except for sunflower. Thus, ΔN at the vegetative growth stage was regulated by shoot growth (CGR), which was related to RW sometimes. Thereafter, ΔN was regulated by SARN with the progression of growth. 2. Based on the cluster analysis of SARN or RW for ΔN, and correlation between ΔN and SARN or RW, crops were classified into three gro...

Mineral characteristics of leaves of plants from different phylogeny grown in various soil types in the temperate region.

The objective of this research was to analyze selected minerals in leavesof plants, belonging to 166 species growing in alluvial, low pH, brownforest and serpentine soils. Mineral characteristics of the soils involved werealso determined.For the macronutrients, in trees grown in alluvial soil, N, P, Ca, and Mgconcentrations of leaves were higher in recently evolved plants than inplants with a longer period of evolution; K concentration remained constantregardless of evolution. In grasses grown in alluvial soil, it was difficult todetect the general tendency of mineral concentration. N, P, and Kconcentrations in alluvial soil were closely related to those in low pH andserpentine soils. Ca concentration in alluvial soil was lower than that in lowpH and serpentine soils. Mg concentration in alluvial soils was higher thanthat in low pH soils, while lower than that in serpentine soil. Therefore, N,P, and K accumulated according to the plant characteristics for theseelements, while Ca and Mg accumulation was strongly affected by the soilproperties.For the micronutrients, in trees, Fe and Mn remained constant regardlessof evolution; Zn concentration was lower in recently-evolved plants than inplants with a longer period of evolution. In grasses, Fe, Mn, and Znconcentrations in Caryophyllids were high. Except for Caryophyllids, Fe andCu concentrations remained constant, Mn concentration decreased withevolution, Zn concentration was higher in recently-evolved plants than inplants with a longer period of evolution.

Mineral characteristics of the leaves of 166 plant species with different phylogeny in the temperate region

The P-N regression coefficient was moderate in Magnoliales,Coniferopsidae, Pteridophyta, and Asterids, but very high in Caryophyllids,and very low in Rosids. The K-N regression coefficient in trees remainedconstant regardless of evolution, and that in grasses was high except forRosids compared with that in trees. The coefficient was very high inCaryophyllids and was very low in Rosids. The N-Ca and N-Mg relationshipwas not estimated at all, suggesting that the mechanism of Ca and Mgaccumulation was completely different from that of N related accumulation.The Zn and Cu concentrations were related to the N concentration.The Al concentration in leaves was negatively correlated with the N, P, K,Ca, Mg, Na, Cu, Zn, Mn, and Fe concentrations, while the N, P, K, andMn concentrations in leaves increased slightly with the increase of Alconcentration in the high Al concentration. The Na concentration in leavesrelated negatively to the P, Ca, Cu, Zn, Mn and Al concentration range.Thus, it was demonstrated that most of the minerals in leaves accumulatenegatively Al and Na indicating that there are antagonistic mechanisms formineral accumulation in leaves among Al or Na and other mineralelements.

Relationships between root activity and N, P, K, Ca, and Mg contents in roots of field crops

Abstract Based on the previous paper (Osaki et al. 1995, Soil Sci. Plant Nutr., 41, 635-647), crops were classified by root characteristics for nitrogen uptake as follows: Group I (small root dry weight (RW) and high specific absorption rate of nitrogen (SARN)): legumes, potato, and beet; group II (large RW and low SARN): cereals; and group III (large RW and high SARN): sunflower. In the roots of field crops subjected to various treatments in a field of Hokkaido University, the nitrogen, calcium, and magnesium contents in roots were relatively higher in group I than in groups II and III. Potassium content in roots was high in maize and sunflower. Phosphorus content in roots in groups I and II increased linearly with the increase of the nitrogen content, and the contents of both minerals were higher in group II than in group I. However, the phosphorus content in group III remained constant or increased slightly with the increase of the nitrogen content. Potassium content in roots in groups I and II did not...

Nutritional characteristics of sago palm and oil palm in tropical peat soil

Abstract To make clear the nutritional characteristics of sago palm (Metroxylon sagu Rottb.) and oil palm (Elaeis guineensin Jacq.) grown in tropical peat soil, minerals concentration, organic compounds concentration, and photo‐synthetic rate were estimated, and the obtained results were as follows. Since, the nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg), and sodium (Na) concentration in mature leaves and trunk were higher in the oil palm than in the sago palm, but potassium (K) concentration was higher in the sago palm than in the oil palm, the minerals (especially N, P, Ca, and Mg) requirement for the oil palm were higher than in the sago palm. This indicates that the sago palm will adapt better than the oil palm to soils with poor nutrients. The manganese (Mn) and zinc (Zn) concentration in leaves of the sago palm and Ca and aluminum (Al) concentration in leaves of the oil palm increased with the increase of aging, indicating that those elements are eliminated from plants through leaf sen...

The Ionomic Study of Vegetable Crops.

Soil contains various essential and nonessential elements, all of which can be absorbed by plants. Plant ionomics is the study of the accumulation of these elements (the ionome) in plants. The ionomic profile of a plant is affected by various factors, including species, variety, organ, and environment. In this study, we cultivated various vegetable crop species and cultivars under the same field conditions and analyzed the level of accumulation of each element in the edible and nonedible parts using ionomic techniques. The concentration of each element in the edible parts differed between species, which could be partly explained by differences in the types of edible organs (root, leaf, seed, and fruit). For example, the calcium concentration was lower in seeds and fruit than in other organs because of the higher dependency of calcium accumulation on xylem transfer. The concentration of several essential microelements and nonessential elements in the edible parts also varied greatly between cultivars of the same species, knowledge of which will help in the breeding of vegetables that are biofortified or contain lower concentrations of toxic elements. Comparison of the ionomes of the fruit and leaves of tomato (Solanum lycopersicum) and eggplant (S. melongena) indicated that cadmium and boron had higher levels of accumulation in eggplant fruit, likely because of their effective transport in the phloem. We also found that homologous elements that have been reported to share the same uptake/transport system often showed significant correlation only in a few families and that the slopes of these relationships differed between families. Therefore, these differences in the characteristics of mineral accumulation are likely to affect the ionomic profiles of different families.

Yield of soybeans as influenced by genetic characteristics, climatic conditions, and nitrogen nutrition

Eleven soybean cultivars, including a set of nodulating and non-nodulating isogenic lines, were tested in a field of Hokkaido University with and without nitrogen application (300 kg N/ha) for 2 to 5 years, and the data of grain yield and yield components were collected. The following results were obtained. 1. Among the cultivars, there was a positive correlation between the grain number per unit field area and the grain yield, while there was a negative correlation between the grain number per unit field area and the 1,000 grain weight. 2. Under favorable climatic conditions the grain yield was higher because the grain number was larger. 3. The yield increase associated with the improvement of the nitrogen status of the plants was due to increases of both the grain number per unit field area and the 1,000 grain weight. The increase of yield at low yield levels was considered to be more related to the increase of the 1,000 grain weight, while that at high levels was more associated with the increase of gr...

Nutritional characteristics of sago palm ( Metroxylon sagus )

The nutritional characteristics of sago palm (Metroxylon sagus) grown in a shallow peat in To Daeng, Thailand were investigated. The contents of nutrient elements, sugar, and starch in each organ, and the net photosynthetic rate of leaves of sago palm were determined at various growth stages. The results obtained were as follows: 1) The macro and micro nutrient contents in leaves of sago palm were much lower than those of field-grown crops. 2) The maximum net photosynthetic rate (µmole CO2 m-2 s-1) at saturating light intensity was significantly lower in sago palm than in wheat, although the longevity of sago palm leaves was 12 times longer than that of wheat. Hence, the amount of accumulated carbon as a function of the net photosynthetic rate multiplied by the leaf longevity was assumed to be similar to, or more than, that of wheat during the growth period. 3) In sago palm, photosynthates were probably stored temporarily in petioles as sugar, transported to the trunk, and then reconstructed into starch. Sixty-one kg of starch was accumulated in the trunk of the mature plant with 250 kg of total dry weight. 4) Since starch content increased exponentially with the decrease of N, P, K, Ca, and Mg contents in trunk of sago palm, it is assumed that starch accumulation in the sago palm did not follow the nutrients accumulation such as in field-grown crops. Nutrient elements, especially N and P were predominantly distributed to the leaves presumably for maintaining leaf function.