Dry Matter Accumulation and Nutrient Uptake by Wheat (Triticum aestivum L.) under Poplar (Populus deltoides) Based Agroforestry System

Table 3

Periodic uptake of nutrients (kg ha⁻¹) by wheat at different distances from poplar tree line.

Distance from tree line (m)	Nutrients uptake (kg ha^−1)
	N	P	K	N	P	K
		3 years			4 years
		30 days after sowing
0–3	3.2	0.48	4.0	3.0	0.36	4.1
3–6	6.6	0.68	6.3	4.0	0.56	5.0
6–9	7.0	0.70	7.2	7.3	0.71	7.3
9–12	6.7	0.75	6.0	7.0	0.70	6.5
12–15	6.9	0.77	5.8	7.0	0.73	6.7
Control^*	6.4	0.76	5.3	6.7	0.70	6.3
		60 days after sowing
0–3	22.3	2.3	28.1	21.3	2.3	31.8
3–6	40.5	4.3	48.6	39.9	4.2	54.9
6–9	42.5	5.8	48.5	43.0	5.6	54.2
9–12	46.2	5.8	52.7	46.5	5.9	51.0
12–15	47.8	6.1	54.3	47.9	6.0	54.1
Control^*	51.3	6.3	57.6	51.4	6.4	57.5
	(2.5)	(0.31)	(2.8)	(2.5)	(0.31)	(2.8)
		90 days after sowing
0–3	76.6	11.3	69.9	76.7	11.7	66.3
3–6	86.2	10.7	71.9	90.2	12.5	77.7
6–9	87.2	12.7	80.9	96.5	13.9	90.3
9–12	93.1	13.1	80.0	97.5	13.8	75.3
12–15	96.4	13.6	82.8	98.9	13.2	75.6
Control^*	98.8	14.7	84.9	99.4	13.3	78.3

^*Age of the trees; ^**recorded 15 m away from tree line; figures in parenthesis are concentration (%) of respective nutrients.