Influence of Soil Fertility Management on Nitrogen Mineralization, Urease Activity and Maize Yield

For studying the effect of soil fertility management practices on N mineralization, urease activity and maize yield, replicated field trials were established in 2015 at Misamfu and Msekera agricultural research stations (ARS) representing two geo-climatic regions of Zambia. The soil at Msekera ARS is a sandy clay loam (SCL) from a Paleustult, while that at Misamfu is a loamy sand (LS) from a Kandiustult. The field trials had three categories of treatments namely legumes, traditional and conventional. The legumes group consisted of researcher-recommended legume-cereal intercrop systems of maize with Cajanus cajan, Crotalaria juncea and Tephrosia vogelii in combination with compound D (10% N, 20% P2O5, 10% K2O) and urea (46% N) at the recommended rate (200 kg ha-1) and half of the recommended rate (100 kg ha-1). Composted cattle manure and Fundikila, a special plant biomass management technique, were the inputs under the traditional category. The conventional category consisted of a treatment to which only chemical fertilizer was applied. Urease activity was determined in surface soil samples (0-20 cm) collected from the field trials after 3 years. For N mineralization, a laboratory incubation study was conducted over 13 weeks. For the laboratory incubation, an additional treatment to which no input was applied was included as control. Application of organic inputs significantly increased the potentially mineralizable N (No) by 127% to 256% on the LS and by 51% to 131% on the SCL in comparison to the control. Similarly, the cumulative N mineralized (Ncum) was twice or thrice higher where organic inputs had been applied in comparison to the control. The No followed the order traditional > legumes > conventional > control, while the mineralization rate constant (k) followed the order legumes > conventional > traditional > control on both soils. The rate of N mineralization was significantly higher on the LS than the SCL. Higher rates of chemical fertilizer resulted in high Ncum and higher maize yield. Maize yield was significantly and positively correlated to Ncum, but inversely correlated to the amount of applied N that was mineralized (%Nmin). Urease activity was stimulated by application of organic inputs and suppressed by higher rates of chemical fertilizers. The type of organic inputs; the rate of chemical fertilizers; and soil texture are factors influencing N mineralization and maize yield. Urease activity was largely influenced by the rate of chemical fertilizer, but not the type of organic inputs or soil texture.

THE REPRODUCTIVE PERFORMANCE OF THREE IMPORTED HOLSTEIN HERDS IN IRAQ

The reproductive performance of three imported Holstein herds in Iraq was investigated in a field study. For this purpose a total number of 889 cows and heifers from three dairy stations that had been on a poor fertility management were palpated rectally for pregnancy determination. Of these, only 289 cows (32.5 %) were pregnant and 541 (60.85 %) were not pregnant. Regarding the non pregnant cows, 385 cows (70.38 % of the non pregnant, 43.3 % of the total) had a normal genital tracts (normal uteri and functional corpora lutea), indicating that they were cycling; the rest had palpable pathological findings; 69 (12.6 % of the total non pregnant) had ovarian inactivity, 56(10.2%) had purulent metritis; 14 (2.55 %) had cervical fibrosis; 12 (2.19 %) had cystic ovary and only two cows (0.36 %) had a mucometritis. The present data indicate low reproductive performance of these herds. Causes of high conception failure in these herds are discussed.

Influence of Different Fertility Management Practices on Productivity and Economics of Forage Soybean

Background: Quality and higher fodder production is one of the important aspects to get higher productivity from live stock. India suffer a net deficiency of 35.6% green fodder, 10.95% dry crop residues and Jammu and Kashmir faces a net deficit of 19% in fodder. The choice to grow cultivated fodder crops during kharif season in Kashmir is limited and are grown generally under rainfed conditions. The major kharif season fodder cereal crops are maize and sorghum and the legume fodder crops are cowpea and soybean. To improve the quality and yield of fodder crops, it is important to standardise production technology for legume fodder crops. Methods: A field experiment was undertaken at Agronomy Farm, Faculty of Agriculture, Wadura of Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir during kharif 2019 and 2020 to study the impact of different fertility management practices on productivity and economics of forage soybean. The experiment comprising of seven treatments laid out in a randomized complete block design with three replications. Result: Application of N, P2O5, K2O (30, 90, 45 kg/ha) along with 0.1 tons/ha vermicompost recoded higher green fodder productivity and growth characters of soybean. However application of N, P2O5, K2O (20, 60, 30 kg/ha) was found economically viable option.

Physiology and modulation factors of ovulation in rabbit reproduction management

Rabbit is an induced ovulatory species, so ovulation takes place after mating. Traditionally, exogenous and synthetic hormonal factors (administered by intramuscular and intravaginal route) such as GnRH and analogues, or different physical procedures (i.e. stimulation by intravaginal cannula) have been used to induce ovulation in females when artificial insemination is applied in rabbit farms. Restriction and public rejection of the use of hormones is leading to the study of the seminal plasma components with potential action on ovulation induction. The aim of the present review is to collect and summarise the strategies used in recent years to trigger ovulation and improve rabbit fertility management with respect to more animal-friendly manipulation methods. Furthermore, special attention has been paid to the use of a semen component (as endogen molecule) such as beta nerve growth factor (β-NGF) in male and female rabbit reproductive physiology. This neurotrophin and its receptors (TrKA and p75NTR) are abundantly distributed in both male and female rabbit reproductive tracts, and it seems to have an important physiological role in sperm maturation and behaviour (velocity, apoptosis and capacitation), as well as a modulatory factor of ovulation. Endogen β-NGF is diluted in the seminal doses with the extenders; hence it could be considered an innovative and alternative strategy to avoid the current exogenous (by intramuscular route) and stressful hormonal treatments used in ovulation induction. Their addition in seminal dose could be more physiological and improve animal welfare in rabbit farms.

Soil fertility management for groundnut in the lowveld of Mpumalanga and north coastal plain of KwaZulu-Natal provinces of South Africa

Smallholder groundnut production contributes substantially to food security in Mpumalanga Lowveld (MLV) and in Manguzi, the northern coastal plain (NCP) of KwaZulu Natal (KZN), both of which are dominated by infertile structureless sandy soils. A study was conducted to obtain information on the chemical properties of the soils to guide fertilizer management for optimizing groundnut production on these soils. Soil samples were collected from representative sites in MLV and NCP, and analysed for pH, calcium (Ca), magnesium (Mg), potassium (K), phosphorous (P), zinc (Zn) and manganese (Mn) in the peg-zone (0-10 cm depth), root zone (10-40 cm depth) and subsoil (40-60 cm depth). The soils were largely acidic, with pH mostly falling below 5.5. The basic cation concentrations were generally low, and so were Zn and Mn concentrations. Nonetheless, with the exception of P and Mn, the soil concentrations of the other nutrients analysed were within ranges considered adequate for vegetative and reproductive growth of groundnut, though Zn was marginally so. General fertility management recommendations to inform agricultural extension are provided for groundnut production on the sandy soils based on the chemical analyses of the soils.