Effect of Corn, Sugarbeets, and Fallow on Zinc Availability to Subsequent Crops
Field observations indicated that Zn deficiency of beans (Phaseolus 
vulgaris L.) was sometimes more severe than expected when 
grown on fallowed soil that was low to marginal in available Zn. 
The objectives of this study were to determine the effects of fallow, 
sugarbeets (Beta vulgaris L.), and corn (Zea mays L.) on Zn availability 
to subsequent crops grown on a Portneuf silt loam (Durixerollic 
Calciorthids, coarse silty, mixed, mesic). The sugarbeet and 
corn plant tops and sugarbeet roots were removed, and 11.2 kg Zn 
ha-1 was applied on one-half of each plot before fall plowing 25-cm 
deep. Beans, sweet corn, or potatoes (Solanum tuberosum L.) were 
planted the following spring. Whole plant samples of beans and 
sweet corn and potato stems, leaflets, and petioles were sampled for 
chemical analyses during the growing season. All bean plants were 
Zn deficient when grown after fallow or sugarbeets but not after 
corn or where Zn fertilized. Potatoes and sweet corn did not show 
any Zn deficiency symptoms or any growth responses to Zn fertilization. 
The average zinc concentration in beans (vegetative development 
stage, V3) following Corn was 20.5 mg kg-1 compared with 
12.5 mg kg-1 following fallow or sugarbeets without Zn fertilization. 
The average Zn uptake by beans (V3) following corn was 1.3 g ha-1 
compared with 0.6 g ha-1 after fallow or suprbeets without Zn 
fertilization. The Zn uptake after corn was even greater than where 
11.2 kg Zn ha-1 was applied to fallow or sugarbeets (1.3 vs. 0.9 g 
Zn ha-1). Enhanced Zn availability following corn persisted 
throughout the growing season and into a second bean crop, although 
at a decreased level. Similar trends occurred with potatoes 
and sweet corn. Soil DTPA-extractable Zn was not significantly 
different after fallow, sugarbeets, or corn. These results indicate that 
Zn deficiency in sensitive crops may be alleviated or prevented depending 
upon the preceding crop grown, and that factors not measured 
by DTPA can significantly influence Zn availability.
Mycorrhizal colonization and nutrient uptake of dry bean in manure and compost manure treated subsoil and untreated topsoil and subsoil
Abstract Eroded or leveled Portneuf silt loam soils (coarse‐silty mixed mesic Durixerollic Calciorthid) have been restored to topsoil productivity levels by manure application, but not by other organic sources such as cheese whey. In dry bean (Phaseolus vulgaris L. cv. Viva), only soil organic matter and Zn concentration of leaf tissue correlated with improved yields. Manure application could potentially increase or decrease mycorrhizal colonization depending on which factors dominate. Manured and unmanured soils from a long‐term field experiment were sampled and mycorrhizal spores were quantified, but there was no significant manure treatment effect on spore numbers. A greenhouse study was conducted to see if manure or composted manure freshly applied to subsoils would facilitate mycorrhizal colonization in dry bean roots compared to untreated topsoil or conventionally fertilized subsoil. Low level colonization (< 5%) was observed 21 days after planting and that increased to 58% by 56 days after planting...
Comparative studies of α-Lactalbumin and lysozyme: Echidna lysozyme
Summaryα-Lactalbumin is a modifier protein for galactosyl transferase in the biosynthesis of lactose and lysozyme catalyses the cleavage of β(1–4) glycosidic linkages. It is now generally believed that α-lactalbumin and lysozyme have diverged from a common ancestor. Comparative studies of these proteins from several species are reported here.The presence of lactose and lactose synthetase activity is shown in mature milk samples from a variety of placental mammals (eutheria) and a pouch bearing mammal (marsupialia). The isolation of the α-lactalbumins involved and their properties are compared.The position is different in the milk samples of monotremes. The α-lactalbumin, lactose and lactose synthetase activity levels in the two platypus samples studied are very low. The levels of lactose and lactose synthetase activity in some echidna(Tachyglossus aculeatus) samples are low, but appreciable in others. No α-lactalbumin is present. The lysozyme activity is appreciable, some samples containing a different lysozyme from that present in others. One of these (designated echidna lysozyme I) is capable of lactose synthetase modifier activity in the presence of bovine “A protein”.The properties of this lysozyme are compared with those of lysozymes and α-lactalbumins from a variety of species and their significance is discussed.