the effect of nitrogen (n) levels on n uptake by high weed densities at early growth stages of corn (zea mays l., cv. double cross 370) was investigated for two years (2008-2009) at the agricultural research station of shiraz university. the experiment was arranged in a split-plot arrangement in the randomized complete blocks design with three replications. two levels of weed control (weedy and...

fifteen kinds of local wetland plants in taihu lake region of china were investigated on their respective growth conditions, biomass allocations and nutrient uptake capacities. the test plants were cultured in 3 l nutrient solutions for 28 days with nh4 +-n, no3 --n and p concentrations of 38.5, 132.8 and 10 mg/l, respectively. mean species total biomass ranged from 1.2-21.6 g/plant with above/...

Incorporation of plant residues in soil affects N and C content and dynamics. This studydetermined the effects of short-term alternative rice (Oryza sativa L.) residue management on Nmineralization and uptake by rice. Pot and laboratory incubation experiments were established byincorporating 15N-labeled rice straw and rice straw compost in paddy soil. The 15N recovered by riceaveraged 16.6%; mo...

Irrigation water is limiting for crop production in arid and semi-arid areas. Furthermore, excess nitrogen (N) application is a source of groundwater contamination. Partial root drying irrigation (PRD) can be used as water saving technique and a controlling measure of groundwater N contamination. The objectives of this investigation were to evaluate the effect of ordinary furrow irrigation (OFI...

the effect on sugar beets of water and nitrogen movement in the soil under different water conditions was assessed over two years (2000-1) at the khorasan agricultural research center. three water treatments (no water stress, continuous stress and primary stress) and three n amounts (80, 160 and 240 kg n/ha) were investigated. the amount of moisture depletion in the water treatments was 50%, 80...

Optimized nitrogen (N) management reduces total N application without sacrificing cropyield. However, the underlining mechanisms have not been well investigated, especially lackingthe evidence from roots. Here we performed a two-year field experiment with maize grownunder zero-N, conventional N and optimized N applications and examined grain yield, N,phosphorous (P) and potassium (K) uptake and...

the aim of this experiment was the study of dry matter and nitrogen (n) accumulation, remobilization and harvest index in different wheat cultivars. five bread wheat cultivars (darya, kuhdasht, shiroudi, tajan and zagros) and two durum wheat cultivars (arya and dena) were studied under optimum growth conditions during 2008-2009 at research field of gorgan university of agricultural sciences and...

ABSTRACT-Water stress is the main cause for crop yield reduction in the majority of agricultural regions of the world because it affects almost all plant functions. The effects of Glomus mosseae on growth, nutrients uptake, and antioxidant enzymes of sour orange (Citrus aurantium) and rough lemon) Citrus jambheri) rootstocks were assessed in sterilized soil under greenhouse conditions.  A three...