Jerzy Navrot

Remedy of lime‐induced chlorosis with iron‐enriched muck

Abstract Muck from the Huleh Valley, Israel (drained peat containing about 35% inorganic material) was enriched with inorganic iron salt and tested as an iron source with peanuts as indicator plants. In a pot experiment conducted with a mountain rendzina soil, containing 63% CaCO3, control plants exhibited severe chlorosis and stunted growth, which were completely avoided by the application of FeEDtHA. Iron‐enriched muck increased chlorophyl content threefold over the control up to a level equal to that of FeEDDHA. Dry matter yield was doubled. Levels of Na4P2O7‐ and DTPA‐ extractable iron after three months of growth, were found to be 2–3 times higher than those of the control and FeEDDHA treatments. A field experiment was conducted in the Bet‐Shean Valley on a rendzina soil containing 42% CaCO3. During the growth period, the Fe‐muck and FeEDDHA. treatments exhibited clear advantage over the untreated plots. Pod and hay yields of the Fe‐muck treatments were about 175% of those of the control and about 80...

Transition metal contamination in the Qishon river system, Israel

Abstract Seven transition metals—cadmium, cobalt, copper, chromium, nickel, lead and zinc—were measured in the waters and the sediments of the Qishon-Gadura river system, Israels second largest. Biologically significant amounts of environmental contamination of Cd, Cr, Pb and Zn are being added to the Gadura tributary throughout its course. While the build-up is a potential biological threat, it is the high pH of several of the effluent waters that inhibits the metal mobility. Ironically, therefore, a sudden stoppage of the pollution (before other corrective measures are taken) appears to present a greater biological danger to the Qishon River and Haifa Bay than a continuance of the pumping of these wastes into the river.

Trunk implanted zinc-bentonite as a source of zinc for apple trees

SummaryThe feasibility of zinc supply to apples (Malus spp. var. Golden Delicious) by various Zn-bentonite preparations implanted in the trunk was studied. A preliminary experiment included four preparations and was conducted in one plantation in 1980. A larger scale experiment in 1981, tested Zn-bentonite (ZnB) and Zn-bentonite + ZnEDTA (ZnBEA) in four plantations in the south, center and north of Israel. Clay tablets were implanted in holes drilled in the tree trunk in April. The youngest, fully developed leaves on the new growth were sampled periodically and Zn content was determined.ZnB and ZnBEA implanted at the rate of 15 mg Zn/cm trunk circumference significantly increased Zn content above that of the control trees until mid-September. The ZnBEA preparation supported significantly higher leaf concentrations than the ZnB preparation. Peak concentrations in trees treated with the ZnBEA preparation were 75.8, 47.4, 38.4, and 23.7 ppm in the four plantations and occurred in May. The Zn concentration in the youngest leaves decreased during the season but there was evidence that in some cases Zn behaved as a phloem mobile element. Soil, climate and previous zinc treatments affected considerably the Zn concentration found in leaves in the four plantations making it impossible to identify a single critical concentration level.No damage to the trees was observed as a result of the drilling and implantation of the clay tablets. Clay analysis at the end of the season showed that about two-thirds of the Zn added to the trees was used. The amount of Zn supplied per tree in the implantation procedure was 80–90% lower than that supplied in the routine spraying operations.

Fixation of Zn65 in some calcareous soils and its availability to tomato plants

SummaryZinc fixation and the availability of native and added zinc in two calcareous soils — a rendzina and a loess — were investigated. Zinc fixation was very rapid and almost complete in both soils. Most of the Zn was fixed in the uppermost layer of soil columns; zinc penetration was somewhat deeper into the loess with the lower CaCO3 content than into the rendzina. Zinc availability was, however, higher in the rendzina than in the loess soil either determined by uptake by tomato plants or by extractability. The possible reasons for the differences in zinc availability in the two calcareous soils are briefly discussed.

Chemical fingerprints of life in terrestrial soils and their possible use for the detection of life on Mars and other planets

Abstract Organic carbon in oxidizable forms and nitrogen are the only elements among some 40 elements studied that are significantly enriched in terrestrial soils as compared to the crust. This enrichment is due to and reflecting life activity in soils, and is characterized by a unique profile distribution. It is suggested that these facts can constitute the basis for the future chemical-biological search for life in planetary soils.

Characteristics of clay as a slow-release carrier of Zn by direct implantation into tree trunks

SummaryA laboratory experiment was carried out to determine the release of adsorbed zinc on bentonite-clay (Zn−B) dried at various temperatures. Two methods were used: (1) extraction of Zn by water, dilute CaCl2 and HCl solution and (2) using pecan limb segments with introduced (at midpoint) Zn−B where the Zn was leached by dilute CaCl2 solution forced under pressure through limb sections.The results showed that by optimized heat treatments in Zn−B preparation it may be possible to decrease the rate of Zn release without significant loss of available zinc.

Tomato plant response to iron supply in various carrier forms

SummaryThe effectiveness of a new carrier for iron supply − Fe+2 and Fe+3 − absorbed to montmorillonite clay, was compared to the more conventional iron salts and chelate carriers by a plant experiment. In the greenhouse experiment, iron absorbed to clay and added to the plant is superior or similar in its effects on plant yield and iron uptake to chelated iron added in equivalent rates and to iron salts added at much higher rates. The possible reasons for the effect of iron-clay are discussed.

Sporulation ofBacillus subtilis as a possible measure of available manganese in calcareous soils

SummarySporulation ofBacillus subtilis ATCC 9799 in nutrient broth was correlated with Mn++ concentrations at 10−7 to 10−6M. This specific response was employed for the bioassay of plant available soil manganese. A correlation between sporulation ofB. subtilis in growth medium supplemented with soil samples sterilized by gamma rays or by ethylene oxide, and growth response ofAvena sativa to added manganese was observed in 5 of 6 loessial and rendzina highly calcareous soil types. No correlation between chemical tests and response to manganese fertilization of this soil could be observed.The possible use of this method for the bioassay of plant-available soil manganese is discussed.